darksky

Ever since starting my tire pressure poll, I've been wondering why Acura has a slight difference in recommended tire pressures for the base TL vs. the Type-S.

TL: 33/32 (front/rear)
TL Type-S: 35/32 (front/rear)

According to motortrend's website, the TL and TL Type-S for 2008 have more or less the same curb weight (3,623 vs. 3,674 lbs respectively). Is it because the Type-S comes with different tires? I thought tire pressure is independent of tire model? Dealerships/local tire shops always use the numbers printed on the sticker in the door as guides when they add air pressure to a tire for example.

References:
MT.com's specs on the TL.
MT.com's specs on the TL Type-S.

Bearcat94

I always figured it was to slightly increase understeer bias in the TL-S.

I force (slightly) more understeer out by reversing the recommendation - I run 33F / 36R.

Will Y.

I assume it's because Acura assumes that the Type-S will be driven a little more enthusiastically than the base (and this applies to the 6M vs. 5A cars as well- the 6M cars have the same F/R pressure differential).

The higher front tire pressure will give more road/steering feel and sharpens tire response by stiffening the tire; the higher front/lower rear pressure lessens the understeer inherent in our FWD platform.

The Navi and Type-S cars have the same Michelin MXM4s as OEM unless the summer tire option was chosen by the buyer.

My 5A has a 32F/32R recommendation on the door panel (changed from '06 onwards to 33F/32R), but I use 37F/34R or 36F/33R since the car feels better to me that way with a minimal decrease in ride quality.

I think you've got it backwards- higher front relative to the lower rear will decrease understeer (most cars, esp. FWD) and make the car handle more neutrally. However, a lower front psi is appropriate to decrease OVERsteer for those few cars that have that characteristic (911, hi-po RWD near the limit, competition cars) to make them handle more neutrally.
See http://www.tirerack.com/tires/tirete...jsp?techid=58&

Try 36F/33R (assuming weather permits) and see if you like that better.

Bearcat94

I'll have to read the tech article, but if that is in fact how it works, it's counter-intuitive.

Consider that as you inflate a tire more and more, less and less of the tire contacts the pavement. The less tire in contact with the pavement, the less traction you have.

Therefore, you'd think, higher rear pressure and a near stock front pressure would decrease understeer/increase oversteer; that is the rear tires would be prone to slip sooner.




That is how one of the local SCCA pro-class drivers explained to me and it seemed to make sense.

(all within reason of course - not suggesting anything "out there" like 20 lbs at one end and 45 at the other.)

princelybug

iTrader: (16)

I've heard both ways of reasoning, but it's always safe to go with the mfr's recommendations. So I always go +3 psi up front.