Air Pressure in 225 tires

Im running 225 tires on my stock Spec B rims. The tps hasnt gone off but everytime i look at the tires they look like they are running low. Since these tires are wider than the stock tires should i be running more PSI?

as long as its above 32 and below 45, do what feels right.

Why 45?

 

Krzys

Most of the 40 and 45 series tires are reinforced and can handle 41 to 50 pounds. Read the sidewall to be sure. You'll get a little bit better mileage but the ride will suffer.

i keep my 225's around 35-37 lbs for 'comfort' commuting and 40-42 for longer road trip fuel efficiency...like mentioned above, the ride is a bit harsher

Why 45?

 

Krzys

 

Max pressure for the tire. You won't need anything close to that;)

I suspected this but MAX PRESS depends on manufacturer and model.

I think mine have 51 PSI as magic number.

 

To be able to answer properly one would need tire load tables and know how much weight sits on front and rear axle and get minimum PSI from this. Then go up for better response if needed.

 

Krzys

I suspected this but MAX PRESS depends on manufacturer and model.

I think mine have 51 PSI as magic number.

 

To be able to answer properly one would need tire load tables and know how much weight sits on front and rear axle and get minimum PSI from this. Then go up for better responsed if needed.

 

Krzys

 

You put 51 psi on tire, and you might as well be on roller skates. What you want is the minimum pressure, that does not allow the tire to "roll" on the "average"..

 

Welcome to the world of suspension tuning:lol:

Random story: My 1997 Jeep Wrangler Sahara got a set of Bridgestone Revo's on them (awesome brand new tire ~5-6 years ago). Shop filled 'em up at around 30 PSI.

 

Steering felt like crap, handling sucked, and generally felt like a drag. I had gone with a bigger sidewall though, so ok. Didn't think anything of it. My brother pointed out that the recommended pressure, per the tire itself, was about 51 PSI (and I'm not talking max pressure).

 

Filled 'em up and they were phenomenal tires.

 

Point being: Find the right pressure for your tire, on your car, with your driving style. For me, who is running 225/45/17 on a car meant for 215/45/17 (my 06 SI), it's about 35 PSI....whereas I'd run 38 PSI on the stock 215/45/17 sizing.

 

Joe

Why 45?

 

Krzys

 

just the upper limit if you do any autox/track driving or want alittle more rim protection if you are in an area with alot of potholes

I'm at the upper end on RE01's 45-47 or so because of the way I drive I can feel the sidewall flex if I'm at a lower psi.

I'm running 32-34 psi in my 225/45/17 Nitto Neo Gens.

 

I originally started out at 40 psi which is what I ran successfully in my Toyo Proxes 4's of the same size but the Nittos didn't handle well at turn in... kind of felt wobbly almost. Turns out they were likely overinflated at that pressure (they're quite stiff in the sidewall) and they were simply rolling on to the flatter portion of the tread. Just a little unnerving. I ran 34 psi at an autox event and the tires didn't rollover onto the sidewall.

Why 45?

 

Krzys

 

tires warm up and can gain as much as 5 psi more than when cold. Most tires limits are any where from 45 psi to 52 psi (check your tire specs).

 

 

As for racers, you want to always aim for the right amount once they get warm. Too much tire pressure causes less tire contact patch while too low will cause too much shoulder scrubbing.

 

 

In other news for daily driving, I normally run higher regardless of what the side door sticker says. I do my own numbers based on the tire wear that I keep track of. If the shoulders look like they are wearing out a tad faster than the middle, that means I'm too low on pressure. If the center is wearing out faster than the shoulders, then that means I have too much. I normally like to fill it up higher than the recommended numbers anyways because your tires' load weight capacity is actually based on the amount of tire pressures you have.

 

As a bonus from my racing background: If I want to have more stability in the rain, I actually drop the tire pressures down just under the recommended pressures. This helps on softening the moment of contact when the tire hits the water, so it reduces some of the hydroplaning effects.. this is definitely more noticable if you have a wider tire.

^ So I'm assuming lower tire pressure in the snow will help also? Or is it not as simple as that?

Depends on the tire

^ So I'm assuming lower tire pressure in the snow will help also? Or is it not as simple as that?

 

If you want to float on top of snow then you decrease pressure (as if driving on sand).

If objective is to get to road beneath the snow then one would need to increase pressure.

 

I think.

 

I am not sure I follow logic to drop pressure to help with hydroplaning.

 

Krzys

My 225 18's feel best around 40psi hot.

looks like they are around 33 PSI. I guess I will take it in and get a little more nitrogen in them