| Author | Message | ||
     John Aravanis Yet to post message Username: krug300 Post Number: 1 Registered: 2-2005 |
My SRH 8685 wears 235-70R-15 Cooper Lifeliners. The shop manual as well as the handbook recomend a tire pressure of 28 lbs.sq.in. This applies to bias ply as well as early radial tires. I now discovered on the forum that the pressures for todays tires should be between 38-43 pounds. Any advise would be welcome. John | ||
| David Gore Moderator Username: david_gore Post Number: 393 Registered: 4-2003 |
John, Tyre pressure is a personal choice depending on your driving preferences: The factory recommendations give the quietest, softest ride at the cost of reduced handling ability and increased tyre squeal if abrupt changes of direction are necessary. Higher pressures will improve handling/steering response at the expense of a slightly noisier and "harder" ride - I used pressures around 36/38psi for everyday driving and 38/40psi for long-distance highway touring for DRH14434 but these are probably too high for a "traditional" owner. | ||
| Adrian Jump Unregistered guest Posted From: 217.205.241.18 |
Following suggestions to increase tyre pressures over that stated in the handbook posted on the UK rrec website, I wrote to Dunlop - Goodyear. There reply was to stick with the vehicle manufacturers' recommendations as a lot of research on pressures and suspension set ups is arrived at between tyre manufacturer and vehicle producer. I can show you the letter if you wish. However that said I do feel there is argument for increasing pressures. At low pressures there are increased slip angles which affect cornering stability. Generally the wider the tyre section the lower the pressure needed, in the case of RR I imagine the pressures arrived at are more concerned with ride comfort than handling. The only question could be if you were involved in an accident would the insurance company try and wriggle out by saying the vehicle was running on over inflated tyres? (Message approved by david_gore) | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 548 Registered: 4-2003 |
Adrian, As a noted member once pointed out, the car manufacturers prefer that you crash in comfort ! The answer from a tyre manufacturer will always pass the buck back to the car manufacturer and uphold the pressure recommendations printed in the vehicle handbook. Why should a tyre manufacturer make any guesses on a vehicle's dynamics regardless of what is best for the tyres ? I do go with David Gore's preferred tyre pressures as a minimum personally. | ||
| John Dare Grand Master Username: jgdare Post Number: 191 Registered: 12-2004 |
Dont get too paranoid about tires pressures laddies. Unless they are "flat at the bottom" ("Michelin" style) and/or you fancy yourself as a high speed specialist, just pump them up to about 30lbs and see how it all "feels". A few founds "either way" simply doesnt matter except to those who like to make a "science" out of the issue. F1 cars are different. Just like, "Which OIL is BEST?" can keep you awake at night, so too will trivia such as, "28,30,32,34 psi??" etc etc. | ||
| Robert Wort Grand Master Username: robert_wort Post Number: 116 Registered: 12-2004 |
I ran 40 psi on Michelin radials on my old cloud and they lasted over 100,000 miles. The ride was good, the road holding was good and they lasted a heck of a lot longer than when I had them on lower pressures. By the way, if you are changing from cross-ply tyre to radials, always put at least an extra 2 psi above the cross ply pressures. 4 to 6 psi would be even better. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 549 Registered: 4-2003 |
So, Mr D, tyre pressures don't matter ?? Pull the other leg. With the tyres being the primary vehicle-to-earth interface, that's a tall story is it not, especially on such a fundamental primary safety-relevant matter ? Don't forget the Kleber tyre fiasco. That poor company was forced to make a public statement effectively overruling certain Australian vehicle manufacturers' pressure recommendations, upping the minimum by around a whopping 6psi after some spectacular blowouts mainly in NSW at just 90km/h. | ||
| John Dare Grand Master Username: jgdare Post Number: 192 Registered: 12-2004 |
RT. Please do not lead the witness. I did NOT state that "tyre pressures dont matter", merely suggesting that one can become too pre-occupied with tire pressures, alluding as I was, to S/Shadows, which was the SPECIFIC vehicle in the question posed by John A. under this thread. I believe that it is decidedly safer (for everyone!) to be driving my Shadow at "normal" safe speeds (ie generally as per posted limits ) with tire pressures "out" by a miniscule lb. or two, as opposed to someone, who, presumably with EXACT "scientifically" calculated (?) tire pressures, drives upon public roads at the vehicles maximum speed, with "clicks" ranging from 200 to 275 kph. | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 321 Registered: 9-2004 |
John Dare as you note that i drive within the speed limits but do have much power to put the car through its paces throughout the highways and byways. Note the handling is superb,i can only put this down to not having a lopsided dog of a car running on remoulds with pressures out a lb or two or more. I go with Davids pressures and always check the pressures before my journeys. If im on the auto routes etc at speed i increase the pressures to 40lbs. As stated tyre sizes and type have different pressures. Regarding oils,they have moved on since the 20/50 of years ago, so it is a must for the improved oils[synthetic] to be used but of course not in a clapped out engine that fumes its way around to its destination with luck. | ||
| John Dare Grand Master Username: jgdare Post Number: 193 Registered: 12-2004 |
Thank you for your contribution PL. I can think of many cars which should (or need) to be "put through their paces throughout the highways and byways", as you suggest (with all due regard to safety/driver ability etc) but seriously doubt that a boxy 2.2 tonne Shadow (or Spirit) would be one of them. You add, "handling is superb". I think not, given the legions of international road testers who have decried Shadow "handling" since its introduction, notwithstanding the minor improvement delivered via Harvey Bailey type "handling" kits, evolving in part, with the overall marginally improved Shadow 11. Accordingly, I believe that your glowing references are best reserved for other cars, even the lowly (relatively) XJ6 ("Grace, Space and Pace etc") Re tire pressures, if you tow things around you might need higher (rear) pressures, remembering also, that tire pressures increase as the tires become hotter at speed, and in any event are (as noted earlier) merely a matter of personal preference. Although you raise the vexed issue of synthetic oils, I would prefer to address that issue under another thread and will do so when convenient. | ||
| John Aravanis New User Username: krug300 Post Number: 2 Registered: 2-2005 |
So, where does that leave me standing now? I drive my Shadow at leisurly speeds of up to 75-80 miles on the highway. My concern is if the spacific tires (Cooper) which are not known to have the strongest sidewalls on earth, will withstand the scorching Greek tarmac in a few months. A tire with less air and a heavy vehicle riding on it could be dangerous. I took the pressure to 32 and after a 40 mile run at 70-80 mph the tires were quite warm to the touch (ambient temp. 10 centigrade). I'll try 38 next weekend and see if the temperature will be different. I am thinking of using an infrared thermometer before and after the pressure alteration. Or is this getting too scientific? | ||
| Robert Wort Grand Master Username: robert_wort Post Number: 117 Registered: 12-2004 |
Dear me John D., I certainly don't think that My Spur is a bad road handler. It's not a sports car I grant you but I think its handling is well within the expectations for a motorcar of its calbre. I noticed that (on earlier posts), you regailed Range Rovers as the best British Import. I'm sorry but I must disagree with you. They are known in Victoria as 'Toorak Tractors' and it is so aptly named. It is but a toy with no real use if put through it's paces off road. Granted the Land Rover is quite a different story, but then it's doing exactly what it was designed to do. John Aravanis, How are you dear chap? I had some Coopers on my Cloud before I changed over to Michelins (of which I also have on my current Spur). My advice to you John A. is to remove them from the car, weight them down a little and start a new reef in the Aegean. As you noted yourself, they do have weak sidewalls, they also develop rather nasty lumps in the tread as well. I think they are downright dangerous and should be banned ( Where are you Ralph Nader?). Dunlops don't seem to be a great deal better either as they quickly lose grip in the wet once minor wear takes place. For your own safety, I strongly urge you to fit Michelins, They give great grip and seem to last forever ( I got over 100,000 miles on my last Rolls, I was lucky to get 12,000 on Avons and I am not a fast driver). If you can't get them, the next best thing is Bridgestone. | ||
| John Dare Grand Master Username: jgdare Post Number: 195 Registered: 12-2004 |
John A. As noted at the beginning of this thread, tires pressures are a matter of personal choice depending upon ones (general) driving preferences. I have had "Bridgestone" tires on my car (with approx. 32psi) and I am satsified with the overall performance of the car in terms of ride etc. together with tire longevity etc. The question of "best" tire and "best" pressure will invite thousands of "answers", few of which will necessarily be correct for a specific application/location. Talking to other owners in your region may be of assistance if your are concerned about ambient temperatures/road conditions etc. Robert W. My reference to handling was (as is often the case) "in RESPONSE", whereby I maintained that Shadow/ Spirit (incl. Range Rover!) are not the kind of vehicles that are normally "put through their paces" with flamboyant enthusiasm/"gusto" (upon open roads) in the manner of sports oriented "wind in the hair" MGs etc., or "sport" (Le Mans) developed saloons such as the nimble and agile, XJ6. I did not say that our cars handling was "Bad", but simply sought to remind people, that by comparison, R-Rs (and similar large, heavy saloons of their genre) are not sports cars/saloons. Furthermore, I did not say that Range Rovers were "our" best British import, but rather, that they were (arguably) Britains best EXPORT; if of course, your overlook Shepherds Pie and Guinness (incl. Radar, which is why we can still enjoy both!) | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 322 Registered: 9-2004 |
John A,Good thinking on the infared thermometor. Regarding the tyre pressures being a personal choice if you put them to28-30lbs and drive at 70/80mph on long bashes in the hot climate with a loaded car i would be very wary of them over heating. Go for 38/40lbs in the heat. It would indeed be interesting to do some speed tests with the infared thermometor. To cold here at the momment UK. Ignore the above posting of Pie Guinness etc. | ||
| Robert Wort Grand Master Username: robert_wort Post Number: 118 Registered: 12-2004 |
Shepherds Pie and Guinness sounds good to me John  | ||
| Jonas Trachsel Unregistered guest Posted From: 213.221.255.237 |
Dear All May I add my penny worth to this discussion. All that has been written so far is correct, I too agree that manufacturers tyre pressure "prescriptions" are generally too low in favour of a comfortable ride. I have learned many years ago to pump my tyres by reading the wear pattern. The aim is to get uniform tread wear over the whole width of the tread. Almost irrespective of car/model/tyre brand and type I have to increase tyre pressure of the front wheels by about 0.5 to 0.7 bar, the rear ones by about 0.2 bar. For holiday tours with a heavy trunk I up the pressure another 0.3 bar all round. Possibly this has to do with my driving style, as my son and my brother both have to increase the pressure by 1.0 bar or more, whereas the Opel of my wife requires a mere +0.3 bar front only. Of course, the riding comfort suffers some, but this is rewarded by increased Miles-per-tyre and increased stability in corners. Reading the wear pattern of the tyres has even led my son to adjust the track of his front axle (toe in/out) to a value slightly outside the manufacturers recommendations to achive a uniform wear pattern. Therefore I think that the recommendations in this thread are only a starting point, as you will have to find out what is correct for your combination of driving style, car model, tyre brand, load, comfort requirements.... This method has one small draw-back: You have to drive quite a stretch before the wear pattern is readable, it has to "set in" first. Jonas (Message approved by david_gore) | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 559 Registered: 4-2003 |
Jonas, I couldn't agree more. The only realistic pressure recommendations I have seen from Crewe started with the Turbo R. Recommended is up to 2,3/3,1 bar front/rear, that's 33/44psi. Even that is on the low side in my opinion. The recommendation was the result of a very pushy design engineer hired by Crewe with a clean mandate to optimise the handling of these beasts, and after considerable high-speed testing. He got his way, but only just, and the pressures were finally printed in the handbooks. The Avon design is very old now, so I run high-spec Michelins (OK it's a Turbo R, but a useful guide), which meant buying 17" rims as only Avons are available in a legal 15" size and load/speed rating for these cars. Shadow owners are lucky that they can choose excellent Michelin or Bridgestone in 15". The Cooper tyres (incidentally the Avon parent company is Cooper) usually seem OK as a cheap and cheerful solution. Being a 101T rating, they are right on the legal limit speed and weight wise, but are fine as a city tyre. Fantastic tyres, Michelins, and I run 2,4/2,8 (35/40) under normal city conditions and up to 120km/h motorway conditions, but could well increase the fronts a little. The Bridgestones on the T-Series run very happily at 35/38 under all conditions. Both Michelins and Bridgestones give phenomenal mileages and are vibration free. As Jonas mentions, wear patterns are very important. I have always found that the best starting point is with high-end tyre pressures and the toe-in at the minimum recommended. There is plenty of literature available on wear pattern diagnosis, and alignment out of original specification is perfectly legitimate in many cases. | ||
| John Aravanis New User Username: krug300 Post Number: 3 Registered: 2-2005 |
Sent an e-mail to Cooper USA who in turn forwarded it to the Greek representative. I had a very interesting talk with her during which she advised that I should stick to 28-30 psi with Coopers BUT why doesn't the car wear Avons? And why 235's on a 1970 Shadow when the car should have 205's. I checked the shop manual and the owners handbook and verified that the tire dimensions recommended by the manufacturer are 8.45-15 (which is 205/70-15 if I am correct). I am therefore now tempted to go for the 205 size, although I don't know how the car will look or handle with the narrow dimension. Any experience? | ||
| John Dare Grand Master Username: jgdare Post Number: 199 Registered: 12-2004 |
Hello John. I think my car (SRH 8058) has 225s, regretting I am unable to check it since it is presently at a holiday home. I do recall trying 235s (or close) some years ago but they looked ridiculous i.e too "full"/large for the wheel arch openings. Anyway, despite being told that I am "wrong" yet again, I have (I believe) 225 "Bridgestones", that I check every few weeks to about 32psi.,rarely requiring any adjustment and they have a good overall appearance with the white walls etc. Tire "problems". What are they? | ||
| Robert Wort Grand Master Username: robert_wort Post Number: 119 Registered: 12-2004 |
You have good tyres John. Second only to Michelins. I stand by my opinion (from personal experience), that these are the only two brands worthwhile on our cars. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 560 Registered: 4-2003 |
John A. Tyres have moved on since your car was built and the literature was printed. There is no right or wrong size I suggest, but we all have our own opinions. For reference our '72 SBH13247 has run them all. Crossplies are clearly out for all but city and show use. We ran Avon 235.70x15 for some time. The wear rate was not impressive, but they worked and looked fine. They were light years ahead of the cross plies and the 205s. Then I switched to Michelin 215.75x15. They were even far better and lasted much longer. The smaller size did not degrade performance, quite the reverse. I think that the 215s are ideal for these cars personally, but have not tried the promising 225 size yet. Then I switched to Bridgestone 215.75x15 with much the same or even improved result. I run the same tyres on my R-Type by the way (specially made rims). Many people, especially in the USA, swear by Bridgestone 225s. For all cars prior to the 1974 series (chassis 18268) it would be no surprise to find them to be optimum. So, my choice in future would be 1) 225 and 2) 215 sizes depending on availability. Also, my first choice is Bridgestone, but others will prefer Michelins. I think there is not much in it as both are brilliant. Both come with white bands. If you don't want the white band, simply have the tyres mounted with the bands on the inside. As for cross plies and 205s, I would never consider those antique tyres these days. | ||
| Jonas TRACHSEL Yet to post message Username: jonas_trachsel Post Number: 1 Registered: 2-2005 |
To David Gore: Thanks for getting me registered. Although I am not a member of the RROC(A) I now feel more comfortable to use this forum. To Richard Treacy: You write in your post of Feb. 24 that Crewe recommends for Turbo R's the higher tyre pressure for the rear wheels. I think that these cars are considerably front heavy and have a tendency to understeer. Although I have no personal experience with these cars, I feel that this constellation just cries for reversing tyre pressure front to rear. But as I wrote on Feb. 22, this may depend on personal driving style. I no longer do "rear wheel steering" with my heavy right foot as I used to when I was just 22. Nowadays I prefer rolling through the bends and accelerating on the straights. It is strange (IMHO) that most super sports cars have bigger, fatter rear wheels, not only the rear engined ones. My brother's Ferrari 550 Maranello is such an example. This car eats the front tyres at double the rate as the rear ones. This is another hint that the front tyres often are underinflated when done to the manufacturers recommendations. But the narrower front tyres in this case may probably be justified for wet driving (aquaplaning) and thus be a compromise. Jonas | ||
| Gordon Norris Yet to post message Username: crewes_missile Post Number: 1 Registered: 2-2005 |
Interesting thread, but I would go with what David Gore and Richard Treacy have recommended re pressures. The tyre is your only physical link to the road, and pressures are vitally important, but sadly oft dismissed as unimportant. I wouldn't go so far as to chastise John Dare as he has given a worthwhile opinion of an admittedly reserved driver, and has mentioned "reasonable" pressures of 32 or so, (I've seen some twits running 20-24 ON PURPOSE " because it's more comfortable") but it is not suitable for my own more "spirited" (no pun intended!) driving of my Turbo R. By the way Jonas, what you say is correct, but I think the reason for the high rear pressures recommended for the Turbo R is beacause of the massive torque and inertia of these cars: lower pressures tend to cause tyre distortion on acceleration(seen a dragster's sidewall crease on takeoff?)and tyre-on-rim slippage.  | ||
| Bill Coburn Grand Master Username: bill_coburn Post Number: 346 Registered: 4-2003 |
Ah Gordon, the mills of great age were cranked with your closing remark. Many years ago in a well known Sydney establishment a very nice Silver Cloud something was delivered for a service. When it came to the final items on the list, no valve cores could be found. Ever resourceful, the wheel covers were removed and lo there they were some radians around the wheel from where they were intended. A canny diagnosis prompted a not normally performed wheel balance in that particular service and lo none of the wheels would balance. All four tyres were out of round. The owner was interrogated on arrival and finally admitted that he had done a wheels locked stop from some astral speed on some very rough bitumen. The wheels stopped alright but the wheel covers kept going at least for a bit of a rev! And that Sir is why the Shadows have a peg on their hub caps to stop such a happening!! How's that for useless info eh!!! | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 573 Registered: 4-2003 |
Jonas, Your logic is almost certainly fine from a pure loading perspective. However, once vehicle dynamics come into the picture it all quickly changes. R-R stressed, at least for all post-war cars, that the rear tyres must always be inflated to a higher pressure than the front ones. This is true of every conventional front engine, rear drive make of car I can recall too. Front- and all-wheel drive are other matters. Most conventional drive arrangements put more weight at the front, naturally causing understeer. Along with suspension design, the manufacturers reach a safe level of understeer through relative tyre pressures, higher at the rear. This is true for Silver Shadows and Turbo Rs alike. The Turbo Rs in particular underwent extensive development testing, and the engineers got their way in running higher pressures than on Silver Spirits, but still higher at the rear than at the front as on a Silver Shadow. The Turbo handbook stresses the importance of this, citing handling balance and safety as the reasons. Higher rear pressures in fact reduce the usefullness of inducing power oversteer, and the handling balance makes the car safer in critical situations such as driver error. By contrast, oversized rear tyres, particularly with a rear engine like on a 911, are there to reduce natural oversteer. Remember the early Porsche 911s ? They were known to be a handful on the limit with enormous and erratic oversteer before Porsche fiddled the suspension and fittet oversized rears as standard. Ground-up high performance cars are probably all special individual cases anyhow. Hotted up sedans from BMW M3s to Bentley Turbos, however, all seem to follow the same tyre pressure pattern as eachother and of their origins. | ||
| John Dare Grand Master Username: jgdare Post Number: 201 Registered: 12-2004 |
Hello Jonas. Your brother is fortunate to own a true performance car such as the 550 Maranello and if I owned one I would be as pedantic about tire pressures as I would be on my own 72 911S, as I imagine would also be the case with the legendary BMW M3, which one motoring writer recently described as, "the closest thing you will get to an F1 racing car". I do not believe that any R-R/B car can seriously be compared from an overall performance perspective with any of these three cars. I include the Bentley Turbo (having now been mentioned) such large, 2 tonne plus sedan cars being aerodynamically/weight challenged compared to say the three "Euros" or the current, dynamic "Continental" GT. Whilst Crewes vehicles were perhaps the unique expression of a superbly built, bespoke 4 door passenger motor car (with Turbo variants being brisk in a straight line) they were dynamically compromised when compared to the 550/911/M3 etc., as a very fast drive through the mountains (wherever) would surely attest, and where "optimized" tire pressures would be of undoubted importance. Whilst neither of the three European cars were up to the outstanding build quality (body construction/ detail appointment and material standards) of Crewe, they remain true "performance", cars and demand close attention (and perhaps individual experimentation) with "precision" TIRE pressures due to the GENERAL manner of which they were (and typically are) driven by their owners over varying locales/routes/terrain etc. I respectfully suggest that most owners of Crewes finest (particularly S/Shadow) generally exhibit a different, non "competitive" style of driving in a comparatively routine environment, thereby reflecting the basic nature (and less "demanding" REQUIREMENTS; such as "exact" tire pressures) of the car, which is why I dont "drive" my 30+ yo Shadow (being the SPECIFIC vehicle TYPE originally under discussion in this particular thread) like the 30+ yo 911. In any event, I wonder how many owners who might be obsessed as to whether or not their pressures are "out" by a pound or two, are aware of the EXACT condition of their shock absorbers, for if the tire isn't on the road, its pressure would seem to be rather irrelevant. (Message edited by admin on March 04, 2005) | ||
| Gordon Norris New User Username: crewes_missile Post Number: 2 Registered: 2-2005 |
Ah John, you have picked another "pet peeve" of mine and you are absolutely correct about shock absorber condition. However, a simple point: as 90%+ cars out there probably have neglected/forgotten/or otherwise sub-standard shock-absorbers, if their tyre pressures are correct at least they stand a better chance than the combined double-jeopardy of worn shocks and low pressures. Secondly, I am not suggesting a Turbo R could run with a current M3 or any Ferrari through a twisty mountain pass, however I think you do underestimate the handling prowess of the Turbo R which handles precisely like 2 1/2 tons has no right to do! I think Richard would agree, especially as his car runs 17inch Turbo RT wheels like mine, I believe. I can refer you to many a contemporary road report that favourably compared the handling of a Turbo R to many so-called "true" performance cars, and rated it above most performance sedans of it's day. I am fortunate enough to have owned and still own a stable of modern classic performance cars, including a red one adorned with a "cavallino rampante", and yet I am always amazed that the Turbo R handles as well as it does. If you have not driven one, to compare it to a Spirit is like comparing say a modern Porsche's handling to a VW beetle..(OK, so slight exaggeration for emphasis ) By the way, the current Continental GT is equally weight challenged albeit aerodynamically slipperier, and with no disrespect intended at all, I prefer the progressive handling of a Turbo R to that of a skittish and unpredictable pre-computer-controlled-handling 911 that would always fling you backwards into the bushes at the slightest provocation, ...and often without! | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 574 Registered: 4-2003 |
Oh, John, you're a worry to us all. I hope your flag carrier walks a safe distance in front of you as you drive along. | ||
| John Dare Grand Master Username: jgdare Post Number: 203 Registered: 12-2004 |
Thank you Gordon and I appreciate the sincerity of your remarks whilst understanding the points to which you allude. May I assure you that I have respect for Bentley Turbos (indeed most R-R/Bs!) but remain mindful that like all other cars (incl.911/930 etc) they have their limitations, recalling the Alfa "Montreal" whose chassis dynamics could not accommodate the power input. Although I have been accused of being antagonistic or tending to over complicate matters, I do not believe I have initiated the former whilst the latter is usually in response. Accordingly, when John A initially posted his enquiry re ideal/preferred pressures on his 70' S/Shadow (similar to my own) and having the impression from previous posts that he is an airline pilot (car parked on/near tarmac area/aircraft language etc) I attempted to perceive his probable driving style as he "commutes", as do most of us, to his daily employment. In doing so, I considered likely road conditions/traffic volumes(likely speeds attainable) weather etc., which in part explains why the factory handbook offers varying suggestions for tire psi depending upon the cars domicile. That in itself is clear evidence that under normal driving/ambient "conditions", tire psi is not an exact "carved-in-stone" edict of science. I do not seek to complicate matters or attempt to display "informed" knowledge via dissertations replete with "trackside" jargon such as "understeer/oversteer/side "slip" angles/rear wheel "power steering" etc., such being best left to enthusiastic journo's and aspiring, youthful "F1" or Rallye drivers. If your R-R/B has "acceptable" (Shadow; 28-34 psi etc) tire pressures and one does not approach a given corner "WRX" style, then the technobabble is decidedly irrelevant to the average owner who might be more interested in longevity/overall performance, than what pressures are needed for "fast" drives around every corner and/or "red" lining in "the straights", believing that (excepting the "Continental GT) they look rather silly when doing so. The original question related to a 35 yo car, usually driven I suspect, in a normal manner (perhaps I misread it) under commonly encountered routine conditions, as opposed to what a Turbo R can "do" and whats its tire pressures are (or should be) in pursuit of speed oriented "objectives" and/or capabilities. I often see ageing Shadows (and younger Spirits etc) whereby the stab. bar bushes are totally perished (compromising bar operation) with "soft" springs/shock absorbers/imbalanced wheels, all of which make slight variations to tire psi rather pointless. As I remarked earlier, it is akin to asking about the "best" brand/grade of oil incl. frequency of change. The "answers" can keep you awake too often and for too long. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 577 Registered: 4-2003 |
Phew. At it again I see JD. Finding the message is like extracting the back teeth from a live White Pointer. Has it occurred to you that the older and larger the car, the more critical tyres and pressures become ? As with the arguments for ABS, seat belts and air bags, you can never be sure that driving carefully is enough safety alone if the tyres are below par. | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 334 Registered: 9-2004 |
Richard and all but one. Just returned with a high speed escort to and from the City to clear the way in the SS1. Spotted at speed one car that had gone off backwards into a ditch,the car is well known for this type of manoeuvre,we all know about the drivers of them,they just have to crawl along causing a nuisance to every one. Shadow tyre pressures after the above and they are cool to the touch. To confirm your comments on the older tyres. Tyres have a recomended life of six years. There is talk that the date numbers on all the tyres will be a yearly check sometime in the future within the uk. If we all ignore the ramblings of the above TWIT with verble diarrhoea, i am sure he will go away and let this forum flourish. | ||
| John Dare Grand Master Username: jgdare Post Number: 204 Registered: 12-2004 |
Speaking of the "message", it would appear that the thoughtful post of Jonas T (Feb.22nd at 11;22) was largely overlooked or disregarded. Note his reference to experimenting with tire pressures (within a "known" range) to suit your own car(s)dynamics, combined with personal driving style/conditions etc. I believe that is what I have suggested, or at least, thought I had. Thereafter wear patterns can be "read" to calculate (for all PRACTICAL purposes) the probable "correctness" of pressure for the NORMAL daily road use of a passenger motor vehicle such as the 1970 SS under topic. Formula 1 and misc. competition driving is a little different. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 578 Registered: 4-2003 |
Oh dear, Mr Imsomniac JD, Jonas' (practically my neighbour by the way) comment was far from overlooked. Snooze on. |
