How to: 2020 Explorer ST - Performance Tires/Wheels Sizing Guide

[EnergyFX]

How about 305/40 front and 325/35 at the rear with +30? Or will this upset some electronics?

Because of the AWD system you need to make sure your tire DIAMETER is the same at all 4 tires. Depending on rim diameter your at about a 2% difference between those two sizes. Your rear tires would be about half an inch shorter than the fronts. You generally want to stay within about 3/32” for AWD/4WD vehicles to ensure you don’t have undue wear and heat generation in the drivetrain.

Mixing those two sizes would most likely damage your drivetrain over time.

 

[Overmakta]

Because of the AWD system you need to make sure your tire DIAMETER is the same at all 4 tires. Depending on rim diameter your at about a 2% difference between those two sizes. Your rear tires would be about half an inch shorter than the fronts. You generally want to stay within about 3/32” for AWD/4WD vehicles to ensure you don’t have undue wear and heat generation in the drivetrain.

Mixing those two sizes would most likely damage your drivetrain over time.

Yeah, I suspected that might be an issue.
I've got an Audi RS3 aswell, and they're notoriously picky on tire sizes. You risk getting constant traction control activation just by having different tire brands front and rear

 

[peterk9]

How about 305/40 front and 325/35 at the rear with +30? Or will this upset some electronics?

If you are talking about replacing a 255/55R20 with those sizes then it is NOT recommended. The first size would result in a -4.6% difference and the latter would be a -6.7% difference. You want to try and keep the maximum diameter variance to no more than 3% of the OEM size. Also, having different sizes in front and back can cause issues with not only some electronic features but the AWD system as well.

Peter

 

[Overmakta]

If you are talking about replacing a 255/55R20 with those sizes then it is NOT recommended. The first size would result in a -4.6% difference and the latter would be a -6.7% difference. You want to try and keep the maximum diameter variance to no more than 3% of the OEM size. Also, having different sizes in front and back can cause issues with not only some electronic features but the AWD system as well.

Peter

Hehe, yeah I know. You're Mr. 3% in here from what I can tell. However, I won't rip you a new one for reminding me
Personally, I can't decide if I want a 20" setup with offroad tires or a 22" inch setup with road tires. But rest assured - I will have all 4 wheels equal!

 

[NorrisRX]

I would like to run a staggered set up with the following:
Front - 22x9 (+33) with 285/40R22
Rear - 22x10.5 (+38) with 325/35R22
Original wheels were the 20x8.5 with 255/55R20
What would be the best offset for each wheel combination to keep them both tucked and inside the wheel well? Thanks in advance!