Tire pressure

[glenn]

So i finally replaced the tires on my Beetle with BF Goodrich g-Force Sport, 195/55-15 front and 205/60-15 rears. With my old tires I ran 18 psi front and 28 psi rear. I was hoping that the new tires would be stickier but they spin pretty easily. It was suggested that 28 psi rear is too much and I should drop it significantly.

I'm looking for opinions and actual experiences.

[65bug]

Glenn,
     Well you gas mileage is not going to be as good. I would think once the tires get ruffed up a bit they would get better traction. Geez, I run 32 psi all the way around! I run Goodyear Eagle Gt's in the rear and Nankang 145's in the front. The tread pattern looks nice on those tires!

[2manytoys]

I would agree with the practice of running higher pressure than what you have indicated. Unless you are at the track and you want a better bite, I think I would run at least 32 lbs at all four corners. Check the tire sidewall for recommended tire pressure. Your beetle motor will love you for it too. The comparison was made once that helped me. Imagaine trying to pedal a bicycle with low tire pressure versus a bike with fully inflated tires...takes way more energy to turn the peddles on a low inflated tire than a properly inflated tire. I wouldn't try to make up for tire compound short comings in the way of traction by lowering the tire pressure. There you go, just my opinion.

[65bug]

Not to mention handling! Glenn's newer beetle should really shine in the handling department! With under inflated tires, It's not going to help. It won't handle as well. It's really a trade off. My wifes car runs Michelins. I hate them dam tires. They wear for crap. However, they handle bitchen and the ride is quiet. Just a softer tread for sure!

[Bruce]

I think I would run at least 32 lbs at all four corners. Check the tire sidewall for recommended tire pressure.

This has got to be the worst advice possible!  Where did you dream up 32psi?  Is that something Chevy recommended for an Impala?
What basis do you have for ignoring the recommended stagger in air pressure front to rear?

I've never seen any tire that had the proper recommended pressure for a VW on it's sidewall.

[Lids]

My understanding is that tire pressure on a road car is down to weight not the size of tire.

If you run high pressure you reduce the amount of contact with the road, and this will reduce your fuel consumption as your rolling resistance is reduced, but....  it also reduces the effectiveness of your brakes as the car only stops as a result of this friction with the road.  Under severe braking you will increase the chances of skidding and thus not stopping.

I have always run stock pressures, especially at the front.  When I upped the front pressure I constantly locked up the front brakes and skidded even at 15mph.  So i put it back to 18psi, no more skidding.

Of course as you run a wider tire the pressure can increase so that you still have the same tire/road surface contact.  But 32 on the front sounds way to high for me.

[65bug]

Bruce,
      Nice to hear from you So what do you recommend for the fronts??? Close to what the VW owners manual recommends?



Thanks

[TexasTom]

My understanding is that tire pressure on a road car is down to weight not the size of tire.

If you run high pressure you reduce the amount of contact with the road, and this will reduce your fuel consumption as your rolling resistance is reduced, but....  it also reduces the effectiveness of your brakes as the car only stops as a result of this friction with the road.  Under severe braking you will increase the chances of skidding and thus not stopping.

I have always run stock pressures, especially at the front.  When I upped the front pressure I constantly locked up the front brakes and skidded even at 15mph.  So i put it back to 18psi, no more skidding.

Of course as you run a wider tire the pressure can increase so that you still have the same tire/road surface contact.  But 32 on the front sounds way to high for me.

Excellent post ... X2
I run 22-24 F, 26 R.

[2manytoys]

Good point on the tire pressure for the fronts versus the rear. Being that I usually am filling the tire pressure on the fronts of the drag VW (fronts inflate to 32 and rears to 12) There is a huge difference on a street car,...unless the VW has a Chevy  V8 in the front end. Better advice would be to account for front to rear differences in tire inflation need. 32lbs at the front would be way too much. Thanks for pointing that out. On reviewing the manual, and assuming you don't have a V8 mounted up front, the VW manual is a good resource......(how was that for putting it in reverse and back peddling? I need to spend more time in the street VW and less in Drag VW)

[normac67]

I think I would run at least 32 lbs at all four corners. Check the tire sidewall for recommended tire pressure.

This has got to be the worst advice possible!  Where did you dream up 32psi?  Is that something Chevy recommended for an Impala?
What basis do you have for ignoring the recommended stagger in air pressure front to rear?

I've never seen any tire that had the proper recommended pressure for a VW on it's sidewall.

 I agree with you Bruce. Have always run 17 to 18 front ( 145,s ) and 27 to 30 in the rears (205-65 ) If I put 20 in the front it rides like a buckboard!!