Tire size decision

Hi guys,

My 740 came with Pirelli P2000's at 185/65 R15 and I've always fitted the same type & size tires when going for tire change. This time however after I've read about the new Pirelli P6 (not the P6000), I've been tempted to try them. Unfortunately the local Pirelli dealer told me he can't get any P6 at

185/65 R15 anymore, so if I really insist on them I can either get 195/60 R15 or 195/65 R15.

Firstly, do you guys think the P6 is better than the P2000? I look for quietness, smoothness, low fuel consumption and long lasting when I choose tires. Traction is important of course, but I drive my 740 conservatively most of the time... afterall it's not a sports car. I didn't like the P6000 because I've been told the "wave" tread pattern tires are louder than the traditional tread pattern like the P2000.

Secondly, if P6 is really worth getting, should I get 195/60 or 195/65? I'll loose a bit of tire diameter with the 195/60 (and thus ride comfort), but my speedometer & odometer will only over-read by 1% while the 195/65 will under-read by 2.1%... and I prefer having an accurate odometer & speedometer. Or alternatively is there any way I can re-calibrate my instrument to read accurately with the new tire size? _________________ Will '90 Volvo 744 GLT (B230F) - daily driver '73 Volvo 164E - awaiting repair & restoration

Reply to
William Liao
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Have you considered Michelin MXV4 Plus? Based on the criteria you described, they seem like a perfect match. I have had 3 sets on 3 different cars and have been extremely pleased with them. Also, I'd go with the

195/60/15 size ... you will not notice any significant ride reduction quality in my opinion and the spedo error will hardly be noticable .... 1/2 mph off at 50 mph and 1 mph off at 100 mph.

... Larry

Reply to
Larry

And you'll probably find that the speedo has a greater error than you're introducing with the differing tire size. If you can find a measured distance on the road somewhere you can calculate how your speedo is doing now, then pick the tire size that cancels out some of the error. My guess is you speedo reads high, going with the 195/65 tires will lessen the error.

Reply to
Mike F

Re: speedo. I run on "correct" tire dimensions on my s80. When my meter says

140km/h real speed is 128km/h. Thats +9% error. Was same with my previous V40. Here in Sweden, the motorways often have white lines across the lane which are 500m apart - for police helicopters to measure yr speed.... These lines are good use when you want to check yr speedo. distance(m)/time(s) x 3,6=km/h

//Johan "William Liao" skrev i meddelandet news:lFKYa.20899$ snipped-for-privacy@news-server.bigpond.net.au...

Reply to
JohanE

I agree. Superb tires.

Reply to
Joseph Oberlander

The problem is that the spedos here in the U.S. are not recalibrated and they assume you are using European sized tires. What's 4-8% slower driving going to hurt anyways?

My 240 with the manufacturer's suggested tires would read 5-8MPH faster than the actual speed. We have one of those traffic radars in town on a trailer - that shows you your speed - and darn it if the Volvo isn't way off. Driving 45mph(spedo)? Tells me 39. I went past one on a rural road the other day and it read 57mph when my spedo said 65. Egads.

Next set is going to be taller.

Reply to
Joseph Oberlander

Reply to
JohanE

Well, going 58 when you think you are going 65 kind of sucks.

OTOH, might explain why Volvos don't get pulled over as often.

Reply to
Joseph Oberlander

Which 240 and what size tires do you have? It is a common error to put 185/70R14 tires on non-turbo wagons which specify 185R14. This results in a 7% difference in tire circumference and therefore speedometer reading versus actual speed.

Reply to
Timothy J. Lee

I run 225/60/15 on mine. Not sure why anyone in the USA would care about

1-2 mph error in the speedo at 70-100 mph. As stated before, rarely will you find a car that is dead on from the factory.
Reply to
Jack in Dallas

I was going to pop it in my pocket and hop over with it!! I saw another blue one today with a 340/360 at the house as well. I don't think he is VOC but you never know.

Keep up the good work mate, from Peter.

Reply to
Peter Milnes

I ended up buying Pirelli P6 at 195/65 R15. Since I only bought a pair, the guys at the tire shop fitted them on the rear, contrary to the normal practice of fitting new tires on the front. He told me if I'm mixing wider tires with narrower ones, the wider ones should always go on the back. So now I have a pair of brand new Pirelli P6 at 195/65 R15 on the rear and used (but not worn) Pirelli P2000 at 185/65 R15 on the front... and as you'd expect, I feel a pronounced understeer... _________________ Will '90 Volvo 744 GLT (B230F) - daily driver '73 Volvo 164E - awaiting repair & restoration

Reply to
William Liao

So fit the new ones on the front, I do as a matter of course when buying two tyres at a time. You need the front wheels to grip when braking and the slightly wider tyres will also give better grip when cornering.

All the best, Peter.

Reply to
Peter Milnes

I take it you do not have antilock brakes or traction control on the vehicle as they would probably have gone "squirrely" by now with the different tire sizes front and rear. Also, different tire sizes front/rear will cause a 4 wheel drive system to fail prematurely .... for what ever it's worth.

.... Larry

Reply to
Larry

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