ttAmerica RoadsterAWD

Got new tires on my son's 944T. With all the updates and redoing many systems, we finally went with Continental extreme contact. Nice tire. However, we are using the wheels from a 1998 Carrera. Looks great on the 951, but its a 17 inch wheel. So, up front we have the 205/50/17 and rears are 255/40/17. The carrera's inflation pressure does not jive with our cars because we have heavier front ends due to the engine, and lighter rear ends due to the absent rear engine (tranny not as heavy). Since we have essentially 50:50 weight distribution, does anyone have any thoughts on what pressures I should run with our Carrera wheel/tire combo? Spirited street use only.

thanks a million!

jadatis

Pressure advice is all about weight on tire and speed used.
Its to give the tire a deflection , that wont overheat any part of tire, when driving the speed constantly.
This" pigheaded Dutch selfdeclared tirepressure-specialist" can calculate it for you.
Give more info , and I will calculate,
Motor in front, but also frontwheeldrive?
the larger tires behind would expect rearwheel.
find on sidewall of tire if XL/ reinforced/extraload.
aAnd give axleweights weighed and/or GAWR's ,GVWR, empty weight, and max speed you use, and wont go over for even a minute.
also give camber angle ( behind) .

Dan Martinic

I found this during a search and it seems helpful here:

https://toyotires-1524598101.netdna-...s_20151020.pdf

Quoting the original source comment on the above:

"Basically you use your OEM tire specs to look up the corresponding load front/rear. You then use the same table to find your new tires and reverse lookup the PSI from the same load front-rear.
The example they give:

OEM tire: with door sticker saying 32 psi front / 29 psi rear. The table corresponds this tire/pressure combination to 1354 lbs front / 1272 lbs rear.
New tire to handle loads of 1354 lbs front / 1272 lbs rear, the table says you need 35 psi front and 32 psi rear."

From a comment on https://mechanics.stackexchange.com/...on-stock-tires

So, if you want, you can look at the tables for stock sizes and pressures (951 is 36 both front & rear so the 35 values are closest I guess), get the loads, and figure out the pressures for the new sizes.