Tire pressure quandary

[young at heart]

Given my age and car experience I never thought I’d be asking for tire pressure advice but here I am.

I‘ve always run the door-sticker recommended 32# cold all around in my 2020 GT convertible. It has the stock 255/40-19 PZeros on the 19x8.5 black package wheels, rolling on base suspension. I’ve always thought it handled pretty well in the corners and had a good ride too. So I recently snagged a new 2022 GT coupe rolling on the exact same wheels, tires and suspension and I immediately notice the handling is significantly better in the turns and the ride is still very good as well. After a few days I decide to check the tire pressure and it’s at 41# cold all around straight from the dealer.

So, is the recommended 32# too low? The last thing I want to do is replace a set of tires prematurely because of center wear but the handling difference is real.

Where do you guys set your tires for the street? Am I missing something here?

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[mrbydangel]

I almost never follow the door card pressure on my cars. That recommended pressure is a compromise between comfort, performance, and economy. Because I give more weight to performance, I usually go a bit higher pressure, making sure that I am well within the limits of the tire.

 

[shogun32]

I'm very surprised you're getting that much better feel/performance from 41psi. Some tires have soft sidewalls, some very stiff, some in the middle and they all react different to PSI. Feel free to experiment. Ford's recommendations are hardly gospel and given some of their other recommendations, flat out nuts. It is up to the consumer to figure out which is which.

 

[Cobra Jet]

The cold tire psi on the B-pillar decal is correct if running the as built stock tires.

The tire psi will also go up as the tires get warmer while driving, so expect a 2-5psi increase - which is completely normal..

If cold psi is registering 41# on a hand held gauge when stone cold (not the dash cluster), that's way too high, more so if the Tire label shows 32# stone cold. Bring the psi in those tires down to at least 32-33 cold psi, because when driving, the tire psi will increase and you certainly don't need a tire psi of 45# +....

Is the new 22 GT a Premium or does it have same base suspension as your vert?

Also coupe chassis is much more rigid than ANY convertible, regardless of manufacturer. The verts will always have cowl shake and a "sloppy" suspension feel when compared to any coupe of the same make/model/year.

Tires also play a role - does each vehicle have the same size/brand tire?

 

[gadgtfreek]

I had to run my rears around 28-30 PSI on the 2019 PP2 to help traction. Which it did. Ive done the same on the 2021, keeping fronts where they are supposed to be. That being said, buying Pilot Sports for the 2019 made the most improvement in grip.

 

[young at heart]

The cold tire psi on the B-pillar decal is correct if running the as built stock tires.

The tire psi will also go up as the tires get warmer while driving, so expect a 2-5psi increase - which is completely normal..

If cold psi is registering 41# on a hand held gauge when stone cold (not the dash cluster), that's way too high, more so if the Tire label shows 32# stone cold. Bring the psi in those tires down to at least 32-33 cold psi, because when driving, the tire psi will increase and you certainly don't need a tire psi of 45# +....

Is the new 22 GT a Premium or does it have same base suspension as your vert?

Also coupe chassis is much more rigid than ANY convertible, regardless of manufacturer. The verts will always have cowl shake and a "sloppy" suspension feel when compared to any coupe of the same make/model/year.

Tires also play a role - does each vehicle have the same size/brand tire?

Thanks everybody.

CJ, yes the wheels and tires are completely identical between the two cars. The 22 coupe is a base 301a car with standard suspension and the 20 vert is a loaded 401a Premium, also with standard suspension.

I‘m thinking maybe it’d be a good idea to bring both cars to 35# cold with a handheld gauge and see how they feel. Hopefully that wouldn’t be enough to get that overinflated center wear thing started.

 

[NightmareMoon]

The cars are set to 40psi for transport. That explains the 41psi on that new car.


For most tires you want to keep the psi under ~37 or less for handling. 32 psi can get bumped up a couple psi but if you roll on 35 cold I would actually expect accelerated center tire wear.

 

[K4fxd]

I've got mine set at 35 cold. Been like that for 20,000 miles. I have even tire wear.

 

[xSouthSyde]

I used to run 32 all round but after a recent service , I noticed they pumped them to 38 cold(instrument panel). I much prefer how my GT handles with the higher tyre pressure.

 

[glockholiday]

I run 5-10 psi higher than the door sticker on every vehicle I own and only then have I been able to achieve even tire wear. Door jamb is too low for daily driving.

 

[Dana Pants]

I autocross a lot and depending on camber, tire model, and wheel width I have run between 33 and 39 psi front and always very near 33 psi rear. Those pressures are based on a lot of experimentation for uniform tire heat and handling behavior. You might find a bit more front psi makes things generally better, but it’s very unlikely a high rear psi is the right move.

 

[Hack]

The center of the tires will wear faster with higher pressure, but you can still run them that way. You should also get a little better fuel economy with higher tire pressure. Pirelli tires aren't the best and the base Mustang suspension is extremely soft. Once the tires wear out you can buy a better set of tires if you want to improve the grip further.

 

[gadgtfreek]

I keep the fronts on the Mustang at door pressure, rears 3-4 psi lower.

 

[young at heart]

The center of the tires will wear faster with higher pressure, but you can still run them that way. You should also get a little better fuel economy with higher tire pressure. Pirelli tires aren't the best and the base Mustang suspension is extremely soft. Once the tires wear out you can buy a better set of tires if you want to improve the grip further.

I’m not sure I would personally describe the base GT suspension as “extremely soft” but I suppose that’s relative and very subjective. I would say it’s probably a good compromise for the way Ford expects the average street-driven GT to be operated. Other options are available for specific needs.

 

[Hack]

I’m not sure I would personally describe the base GT suspension as “extremely soft” but I suppose that’s relative and very subjective. I would say it’s probably a good compromise for the way Ford expects the average street-driven GT to be operated. Other options are available for specific needs.

I agree it's subjective and depends on what you want to do with the car. Probably if you drive only on public roads and always obeying the rules of the road and never accelerating briskly the suspension is perfect.

I personally think even the GT PP1 is extremely soft. I think it makes the car feel like a Cadillac on the road, which is good for long trips and for rough roads. Extremely comfortable, for sure. But if you step on the accelerator on a curvy freeway onramp you will find the nose of the car launches to the moon and the car rolls around like a Weeble. It's not very good for controlling the vehicle in a "performance" situation. For a car with well over 400 HP, it's not really built to utilize and control the power very well.

The GT350 suspension is about the right firmness for a sporty street car that might be driven somewhere other than public roads. And the FP track handling kit is similar firmness - perfect for a daily driver IMO.

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