dug-mac

Does anyone have an idea as to why Acura changed the recommended pressures on the base TL from 04-05 and 06-07? I believe 04-05 want 32/32 and 06-07 want 33/32. IIRC in 07 they changed the rear sways from solid to hollow with a slightly larger diameter, but this doesn't explain the change in recommendation from 06. Not a big deal, but just curious if anyone knows...

Bearcat94

Any change in weight distribution during the same period?

Could've been a change in the manufacturing/make up of the tire itself. Or maybe they were seeing some pre-mature or inconsistent wear in the tire/tread?

Don't know - just speculation on my part.

01tl4tl

Probably trying to eeek out a tiny mileage improvement for the testing procedure
Same idea behind the switch from 5-30 to 5-20 oil

S PAW 1

With my '01 CL-S, I always ran 1 lb. more in the front than the rears. It handled better, and had longer tread life. For once, maybe Acura listened to their owners
Didn't seem to effect the choice of tires as OE, though

dug-mac

I actually have an 03 TL-S and have been trying to figure out how and why 32/32 can be the best setting when the car has a 61/39 nose heavy bias and fwd. I have to say that after experimenting with all kinds of pressures I do think 32/32 (or something close to that) is best - I just can't understand why. I realize that the extra weight and drivetrain duties might cause increased heat buildup - and therefore effectively increase front pressure under heavy driving - but I don't think this would be the case under normal, moderate driving. Increasing front pressure should reduce the slip angle slightly and give better handling, but I in my experience this car handles best at 32/32 (or maybe 33/32). When I have tried pressures above 33 psi it has felt to me that ultimate grip has suffered. Any thoughts?...

wasupdog

iTrader: (2)

the rear tires always stay cooler than the fronts cus the hot engine does cause heat buildup while you're driving, it doesn't matter if u just drive 5 miles or so. just put your hand in the wheel well and you'll feel the heat from the engine which increases the pressure on the front tires.

i'm guessing this is why we think the fronts should be a higher pressure since the car is nose heavy but the end result is probably that the fronts do run at a higher pressure during driving. the engine stays pretty warm a few hours after shutoff too.

dug-mac

^^
Yeah, you're right about the engine staying warm. Even 3 hours after driving the manifold is too hot to touch. Tomorrow I think I will drive around like a mofo and then check my tires hot - I've never really done that. Acura is pretty sure of themselves with regard to the pressures on the 2nd Gen TL-S. My manual gives tire pressures for normal driving and high speed driving. Interestingly, the recommendation is the same - 32/32...

S PAW 1

That wouldn't be it. ALL cars generate engine heat, not just FWD.

Yakuza70

I find it interesting that Acura recommends 35 front, 32 rear on the '04-'06 6MTs. Why the 3 lb. increase on the fronts over the autos? I would guess it has to do with being a manual (requiring more traction?) but doesn't increasing air pressure somewhat decrease traction but reduces rolling resistance?

Kennedy

iTrader: (2)

Actually, according to the parts catalog, the REAR bar is the same across the 6MT line (hollow, 20mm from 2004-2007)... The AT bar is changed in 2007, maybe that's the difference you're reffereing to.

The front bar for the Type-S was changed from a hollow bar to a solid bar, both at 27.2mm diameter.

Will Y.

The differential between front and rear reduces understeer and makes the car handle more neutrally. My WAG is that Acura is assuming that 6MT drivers are more likely to drive the TLs harder than the 5AT drivers (also a reason for the larger rear anti-sway bar on the 6MT).

That said, I have mine at 36F/33R right now, and sometimes at 37F/34R.

And dug-mac, always measure and adjust the tire pressure when the tires are COLD!
Don't bother doing that when the car has been driven for more than a mile-- the heat will cause inaccurate readings between tires and compared to cold pressures.

S PAW 1

For the same reason they have those settings on the TL vs. the TL-S.
You bascally have an A-Spec suspension, and the balance is much better. Handling is changed a great deal.