3.3TT "Best" performance tire pressures for AWD?

[4wheelpilot]

I've had my GT1 AWD with 18" wheels for for a couple of months.
And still I'm puzzled by the tire pressure recommendations of 36F and 39R.

Why would an AWD car with the same size tires all around and more weight on the front, have tire pressures that are higher in the rear tires?

I'm experimenting with tire pressures...
39 F and R
36 F and R
39F and 36R

Also, just switched out the oem Bridgestones for BFGoodrich Comp G-Force A/S

For owners who have a GT1 or GT2 AWD with 18" wheels, what tire pressures do you run and why?
What do you think is the best tire pressure(s) to optimize handling/ride in a Stinger that's a daily driver?

 

[Ucinn]

I would think what's on the stinger's plate would be the best. They just don't grab these pressures out of thin air. After testing they determine what tire pressures work best with the weight distribution and suspension on these cars.

 

[Tobstertx3]

Interested to see the responses here.

For a GT2 AWD, 19" Rims it is listed as 38F & 36R.

I am now running 20" with the same recommended tire pressures.

 

[eflyguy]

Why would an AWD car with the same size tires all around and more weight on the front, have tire pressures that are higher in the rear tires?

Handling and ride quality

What do you think is the best tire pressure(s) to optimize handling/ride in a Stinger that's a daily driver?

36F and 39R

Experimentation with pressures is certainly a good idea if you don't think the ride quality or handling as where they should be.

 

[eflyguy]

For a GT2 AWD, 19" Rims it is listed as 38F & 36R.

... which goes to show they probably didn't just pull random numbers out of the air. I would have paid close attention when switching from 19" to 20", as I would expect the fronts to be a little soft at 38 - but the wear pattern should help spot that quickly. A generally understeering performance car will quickly shave the outside edges of the fronts if they aren't firm enough - although a stiffer sidewall can help there. What exact tires are you running?

 

[Tobstertx3]

Nitto NT555 G2

 

[Grayt 8]

I've had my GT1 AWD with 18" wheels for for a couple of months.
And still I'm puzzled by the tire pressure recommendations of 36F and 39R.

Why would an AWD car with the same size tires all around and more weight on the front, have tire pressures that are higher in the rear tires?

I'm experimenting with tire pressures...
39 F and R
36 F and R
39F and 36R

Also, just switched out the oem Bridgestones for BFGoodrich Comp G-Force A/S

For owners who have a GT1 or GT2 AWD with 18" wheels, what tire pressures do you run and why?
What do you think is the best tire pressure(s) to optimize handling/ride in a Stinger that's a daily driver?

I was at 36F and 39R. It seemed fine to me for all around driving, ride, handling, and economy. First oil change dealer dropped to 36R and I could tell immediately driving away. The ride is a bit better, and the rear seems a little less nervous/twitchy to me set at 36. I haven't pushed the car very hard since the drop to 36R. I may not like the behavior as much in performance situations. What has your experimentation shown? I'm on the stock Bridgestones still.

 

[Tobstertx3]

@GetYourWheels would probably have a good idea. They seem to be on the ball.

 

[westcoastGT]

I've had my GT1 AWD with 18" wheels for for a couple of months.
And still I'm puzzled by the tire pressure recommendations of 36F and 39R.

Why would an AWD car with the same size tires all around and more weight on the front, have tire pressures that are higher in the rear tires?

I'm experimenting with tire pressures...
39 F and R
36 F and R
39F and 36R

Also, just switched out the oem Bridgestones for BFGoodrich Comp G-Force A/S

For owners who have a GT1 or GT2 AWD with 18" wheels, what tire pressures do you run and why?
What do you think is the best tire pressure(s) to optimize handling/ride in a Stinger that's a daily driver?

How do you like the new tires ?? I've had mine since I took deleivery and really like them

 

[4wheelpilot]

I've had Bridgestone Potenzas on other cars and never liked them. I had the BFGs on my S4 and liked them a lot...great grip in wet and dry.
And all season for the occasional (sometimes more) snow during winters in southeastern Pennsylvania.
So the BFgs on the Stinger are a big step up.
Odd though that my speedometer is 1-2 mph faster than my radar detector and Waze.

btw, when i set rear tires to 39 psi, the back tends to get jittery over uneven roads.
So I'm dropping down to 36 all around for a while.

Also, we want to think that Kia put in a lot of road time to determine the best all around tire pressures.
But it still doesn't make sense that the tire pressures at the back are 3 psi higher when the wight distribution is lighter in the rear.

 

[Tobstertx3]

btw, when i set rear tires to 39 psi, the back tends to get jittery over uneven roads.
So I'm dropping down to 36 all around for a while.

Is there a reason you set the rear tires to 39? When you do this, what are the front?

 

[4wheelpilot]

Is there a reason you set the rear tires to 39? When you do this, what are the front?

For the GT1 AWD with 18" wheels, Kia recommends 36F and 39R.
This is unlike any other performance sedan I've driven (for example, a 2014 Audi S4 with 18" wheels-Audi recommended the same psi front and rear).
With teh recommended 39 psi in the back, the GT1 feels jittery when going over road irregularities, especially when going around turns.
This is the point of my post.

 

[Tobstertx3]

Ahh, I just realized they have significantly different tire pressures for the 18” / 19”

For the GT1 AWD with 18" wheels, Kia recommends 36F and 39R

For a GT2 AWD, 19" Rims it is listed as 38F & 36R.

 

[MisterMac]

It is a mathematical formula involving the weight of the car and the load rating of the tires. Research load and inflation tables, then do the math.

I just swapped out to 98Y XL (245/40/19) all around on my 19 inch GT AWD. The math worked out to between 35 to 36 lbs all the way around to support the car with a full load. I set mine at 35 cold because it is normally just my wife and I without and additional weight.

The stock 19's are 93Y XL front and 98Y XL rear, hence the different front (38) / rear (36) tire pressure.

 

[Kosh]

Nitto NT555 G2

Prob not the best thread to ask this on but how are you liking those tires in the dry and wet?... are they noisy or rough?

 

[eflyguy]

It is a mathematical formula involving the weight of the car and the load rating of the tires. Research load and inflation tables, then do the math.

There certainly can be maths involved, but I want to make sure people don't think it's the same for every tire, driving style, or temperature.

It doesn't work that way. Every tire has different characteristics and road surface and temperature, ambient temperature, driving conditions and expected handling will all affect the "ideal" pressure. There's no one size fits all.

At a race track it is not uncommon to find people adjust pressures by 0.5psi at a time to address specific issues or concerns. It's also not uncommon to find different vehicles with identical tires running drastically different pressures, as a result of subtle differences in suspension, weight, power, driving style, etc. Even identical vehicles (i.e. top level racing like F1) will adjust pressures to suit the driver, based on their braking, line, and acceleration styles.

We don't need to be that precise! Many drivers wouldn't notice much difference, but implying one calculation is going to be the best for everyone is simply not accurate.

 

[MisterMac]

Sorry, buddy. You are pretty smart and I appreciate your moderation, but on this one you need to study up a bit. The manufacturer of the tire provides the load rating information per tire according to size. Using that information, and the vehicle weight rating, it is nothing more than simple math to determine the optimal lbs pressure for that tire on your vehicle. Nothing more, nothing less.....

 

[eflyguy]

Yes, absolutely, I agree. I shouldn't have said "it doesn't work that way" but instead "that only works as a general recommendation for the typical vehicle owner." Very few owners care or even bother to check tire pressures, or would notice the difference.

That said, for the purpose of this discussion where the OP doesn't feel it's handling as well as it should, experimentation (within limits) won't hurt. I'm just trying to illustrate that small changes can have a big effect. Sticking to the manufacturers recommendation is not necessarily going to be the best for handling.

 

[Brandondrums]

I know this is an old thread but I have a 2019 GT2 AWD with staggered 19'' wheels and I've found the fronts to wear on the outside and inside as if they have low tire pressure when running the recommended/stickered tire pressures. I've had to crank the front tire pressure up to 39 and the rear down to 36 to even this wear out. I blame a lot of this on the tires I bought after the OEM (which I still had similar wear but only after some monsterously aggressive driving trips to the mountains). In 2021 everything was backordered and I ended up going with some Firestone Indy 500's simply because I couldn't wait 6-8 weeks for the backorder on Michelins.

Anyway...

Not a lot of threads talk about this uneven wear on the fronts on AWD, most are RWD threads talking about the middle of the rear tires wearing out early on recommended pressures but for me, the fronts end up doing the opposite with inner and outer shoulder wear. I could probably get another 5 or 10k miles if I could even this tire wear out on the front.

All of this is to say I think 36R 39F for AWD on staggered 19" wheels is the proper setup. Only makes sense, most AWD Front Engine cars either call for even pressure or higher front pressure for similar reasons.

 

[Snicklefritz]

^^^That's not much of an adjustment, since the recommended psi on AWD 19" is 38F 36R, you're only 1 psi higher in front.

My experience with Michelin PS4(S) has been consistent. I've had inner edge wear in the rear, outer edge wear in front. A recent alignment might reduce or eliminate the inner edge wear - they took a couple tenths of negative camber out, time will tell.

Too much over-thinking of this is not profitable. Go simple for daily driving, including some fun of course. Cold psi on all four corners is initially set at 40. If this drops when the temperatures do I don't worry about it. If it goes up when temperatures do I might let some psi out.