Nathan007

hello everyone!

i was wondering what happens when you change tire size vs the pressure of air it requires. My car (a 2001 accord coupe -4cyl-) is originally equipped with 195/65/15 tires, with a recommended 29psi of air.

i just changed to some sportier yokohama es100 205/60/15 , do i keep it the same?

thank you

Nathan007

by this i mean my original 4 season has a max press of 35 psi and my new ones max is 40

old man neri

Just go with what is written on you door jam. The pressure that is written on the side of the car is the absolute maximum for the tire. You should never run it anywhere close to that. Do what your car manufacturer suggests.

nsxtasy

Neri is correct. You should set the pressure for what the CAR manufacturer recommends, on the door jamb and in the owner's manual, and do that regardless of the tire size. If your owner's manual or door jamb recommended 29 psi for the 195/65-15, use that for the 205/60-15 too. You can use that as a starting point and adjust (by 2 psi increments) if needed due to uneven tire wear, handling, etc.

The pressure on the sidewall of the tire is not a recommended pressure. It's a maximum pressure for safety. Don't set your tires to that pressure. It's like saying that your car can go 130 mph so therefore that's how fast you think you should be driving everywhere...

Nathan007

thank you very much . dont worry i was running them at 32 psi

ill give it a try at 29

longuyen88

this is weird, since when I was at my first autox event, an instructor told me to put 45psi in the front, and 55psi on the rear. is it ok to exceed the maximum pressure by that much?

nsxtasy

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by longuyen88 &raquo;</TD></TR><TR><TD CLASS="quote">this is weird, since when I was at my first autox event, an instructor told me to put 45psi in the front, and 55psi on the rear. is it ok to exceed the maximum pressure by that much? </TD></TR></TABLE>

No!

However, it is very common to use different (usually higher) tire pressures at an autocross than in normal street use, which (I assume) is what we're talking about here. But that sounds MUCH too high, even for an autocross.

longuyen88

yea, i thought it was much too high, but he said it's ok, and he has a integra that was pretty fast at the event.

the max. psi is 35. Maybe I'll run 35 fr. and 40 rear next time?

old man neri

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by longuyen88 &raquo;</TD></TR><TR><TD CLASS="quote">

the max. psi is 35. Maybe I'll run 35 fr. and 40 rear next time?</TD></TR></TABLE>

If the max PSI on the side of the tire is 35.....do not exceed that. The maximum is actually, cleverly enough, the maximum pressure you can ever put in a tire. If you are racing and really heating up the tires I would go a bit less than the max. Ken can probably give much better advice than me on tire pressures and auto-x.


35 actually seems a little low as the max for a tire. Oh well, I could be wrong.

nsxtasy

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by old man neri &raquo;</TD></TR><TR><TD CLASS="quote">Ken can probably give much better advice than me on tire pressures and auto-x.</TD></TR></TABLE>

Not for autocross. You might ask about autocross pressures in the Road Racing/Autocross forum.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by old man neri &raquo;</TD></TR><TR><TD CLASS="quote">35 actually seems a little low as the max for a tire. Oh well, I could be wrong.</TD></TR></TABLE>

It sounds low to me, too, as a maximum. For example, 35 is actually the recommended pressure for GS-R front tires and for 325i rear tires.

JDM_Acccord

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nsxtasy &raquo;</TD></TR><TR><TD CLASS="quote">It's like saying that your car can go 130 mph so therefore that's how fast you think you should be driving everywhere...
</TD></TR></TABLE>

hahah some people on ht would believe it.

midwest aaron

thats not true, you want to run more tire pressure so the tire doesn't roll over on the side wall. tires with a tall side wall or a soft side wall will roll over easily, thats the reason for running such high pressures. i run high pressure when i auto-x but the max pressure on my tires is 55psi, just remember to lower the pressure before you leave the event.

nsxtasy

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by midwest aaron &raquo;</TD></TR><TR><TD CLASS="quote">thats not true</TD></TR></TABLE>

Yes, it is.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by midwest aaron &raquo;</TD></TR><TR><TD CLASS="quote">you want to run more tire pressure so the tire doesn't roll over on the side wall.</TD></TR></TABLE>

Maybe, but only by 5 psi, maybe 10 psi MAX. You don't increase it by 20-25 psi. Not only won't that help performance, but it's UNSAFE. Don't be stupid.

JDM_Acccord

80 psi ftw!