3.3TT To those with awd and aftermarket wheels

[Paska Omena]

What happens if i run 245/35/20 275/35/20
The side wall being the same size as the front

Likely bad things would happen, because side walls are NOT the same size. 245/35 and 275/30 are close to same size. Profile is a percentage of the width, so 245/35=85,75mm 275/30=82,5mm when 275/35=96,25mm

 

[JEOS MS]

Likely bad things would happen, because side walls are NOT the same size. 245/35 and 275/30 are close to same size. Profile is a percentage of the width, so 245/35=85,75mm 275/30=82,5mm when 275/35=96,25mm

Likely bad things would happen, because side walls are NOT the same size. 245/35 and 275/30 are close to same size. Profile is a percentage of the width, so 245/35=85,75mm 275/30=82,5mm when 275/35=96,25mm

So i have a stinger awd model could i just swap the rear tires to 275/30/20 from a different brand

 

[MerlintheMad]

So i have a stinger awd model could i just swap the rear tires to 275/30/20 from a different brand

You would want at least a 9" wide wheel. The OEM 8.5" is going to allow too much sidewall flex to give good handling. 9" to 10" wide is the recommended size for that tire.

 

[JEOS MS]

Likely bad things would happen, because side walls are NOT the same size. 245/35 and 275/30 are close to same size. Profile is a percentage of the width, so 245/35=85,75mm 275/30=82,5mm when 275/35=96,25mm

Likely bad things would happen, because side walls are NOT the same size. 245/35 and 275/30 are close to same size. Profile is a percentage of the width, so 245/35=85,75mm 275/30=82,5mm when 275/35=96,25mm

You would want at least a 9" wide wheel. The OEM 8.5" is going to allow too much sidewall flex to give good handling. 9" to 10" wide is the recommended size for that tire.

So i have have after market wheels 20x9 and 20x10.5 245/35/20 and 275/35/20 i bought the same aspect ratio not knowing it mattered and now I’m wondering if i can just replace the rear with tires and keep the front since I already bought them

 

[JEOS MS]

So i have have after market wheels 20x9 and 20x10.5 245/35/20 and 275/35/20 i bought the same aspect ratio not knowing it mattered and now I’m wondering if i can just replace the rear with tires and keep the front since I already bought them

I don’t want to damage my awd system so I’m thinking swapping just the rears with 275/30/20 with a different brand. Instead of buying. Whole new set from the same brand

 

[MerlintheMad]

I don’t want to damage my awd system so I’m thinking swapping just the rears with 275/30/20 with a different brand. Instead of buying. Whole new set from the same brand

Since you are wanting to maintain the same OD front and rear as close as possible to OEM, you could just stretch the sidewalls a bit by going with your 10.5" wide wheel. The recommended max width is 10" for that tire you want to use, but that isn't set in stone like a commandment. You might not like the "stretched look", though: and then again, it might not look stretched enough to matter. Why can't you buy a pair of rear tires the same brand as the front tires?

 

[JEOS MS]

Since you are wanting to maintain the same OD front and rear as close as possible to OEM, you could just stretch the sidewalls a bit by going with your 10.5" wide wheel. The recommended max width is 10" for that tire you want to use, but that isn't set in stone like a commandment. You might not like the "stretched look", though: and then again, it might not look stretched enough to matter. Why can't you buy a pair of rear tires the same brand as the front tires?

They don’t have the 275/30 the aspect ratio would be the same as the front. Which is 245/35 and rear 275/35. So i might have to miss match brands to get the fit I want i just dont want the car awd system starting to fail with because of the different tread pattern on the read compared to the front

 

[MerlintheMad]

They don’t have the 275/30 the aspect ratio would be the same as the front. Which is 245/35 and rear 275/35. So i might have to miss match brands to get the fit I want i just dont want the car awd system starting to fail with because of the different tread pattern on the read compared to the front

Tread pattern differences won't affect the AWD system; only different OD mismatches will threaten the AWD system. Handling, now, that is a different story. You would not want to mix and match summer and A/S front and rear (although I know a Stinger driver who did this and seemingly without issues as far as he could tell). If you have A/S all four corners, or summer at all four corners, you could look at the tread patterns and match the two brands up as closely as possible: also, get advice from the tire/wheel pro shop in your neighborhood: that's bottom line what I would do before deciding to buy.

 

[JEOS MS]

Tread pattern differences won't affect the AWD system; only different OD mismatches will threaten the AWD system. Handling, now, that is a different story. You would not want to mix and match summer and A/S front and rear (although I know a Stinger driver who did this and seemingly without issues as far as he could tell). If you have A/S all four corners, or summer at all four corners, you could look at the tread patterns and match the two brands up as closely as possible: also, get advice from the tire/wheel pro shop in your neighborhood: that's bottom line what I would do before deciding to buy.

Ohh I didn’t realize the tread on the front and rear could be different. Thanks alot for the feedback u really helped me

 

[SRV]

They don’t have the 275/30 the aspect ratio would be the same as the front. Which is 245/35 and rear 275/35.

I would NOT run that combo for AWD.

Use this to find a front/rear tire combination whose diameters and revolutions per mile are almost exact:

Tire Size Calculator

The best tire size calculator. Use our tire size calculator to find tire size specs and suggested tire sizes. Then check prices for all available tire sizes.

tiresize.com

 

[D.J.]

As an option only - not a recommendation, just an option.

You can just pull the AWD fuse in the engine compartment to completely disable the electronic transfer case while you consume these tires in RWD only mode. No damage to the transfer case clutch pack can occur. It will be for all intents and purposes, inert (while the fuse is removed). No power to the clutch pack = no AWD

Then, once these tires are consumed, purchase a more AWD friendly set (size) of tires, and reinstall the AWD fuse to re-enable the AWD functionality.

No money wasted

 

[SRV]

Well, here is my story about buying tires for AWD. I've never had an AWD vehicle before, so I never even thought about keeping the diameters equal front to rear. My car is a 2022 3.3 GT2 AWD.

I bought rims with the following specs:

09.0 x 19 et33
10.5 x 19 et48

..and bought the following tires:

Continental ExtremeContact Sport
255 x 35 x 19 = 26.0" - 775 revs per mile
305 x 30 x 19 = 26.2" - 770 revs per mile

The above specs came from Tire Size Calculator:

Tire Size Calculator

The best tire size calculator. Use our tire size calculator to find tire size specs and suggested tire sizes. Then check prices for all available tire sizes.

tiresize.com

The diameters and revs/mile don't seem like much of a difference, but according to my research reading the Audi, BMW, etc. forums, in order to minimize wear and tear on the transfer case and differential, it is best to keep front/rear diameters to 1% or less. Additionally, I didn't want to mess up my warranty and possibly have a problem due to the mismatched diameters.

Consulting the Tire Size Calculator, I found that the following works with a 305:

265 x 35 x 19 = 26.3" - 767 revs per mile
305 x 30 x 19 = 26.2" - 770 revs per mile

Unfortunately, it has been documented on this forum that a 265 will not fit up front. To confirm, I installed my 255 x 35 on the front and checked the clearance, and there was hardly any clearance, maybe 0.2", between the tire and the shock body, so there was no way a 265 would work - grr. And using a 3mm spacer would push the rim too far out past the fender.

Back to the Tire Size Calculator, all I had to do was buy 295's for the rear:

255 x 35 x 19 = 26.0" - 775 revs per mile
295 x 30 x 19 = 26.0" - 777 revs per mile

That combination is perfect!

But, problems again - Continental does not offer a 295 x 30 x 19 ExtremeContact Sport tire - what's up with that?

I could have bought Michelins, etc. in that size, but since I live in Wisconsin which has colder temperatures in spring and fall, my first choice was to run all-season tires, but there are no 305 19's and why I initially went with UHP Summers.

Finally, I settled on the following all season:

Continental ExtremeContact DWS 06 Plus
245 x 35 x 19 = 25.8" - 784 revs per mile
285 x 30 x 19 = 25.7" - 784 revs per mile

I was concerned that a 285 would be stretched on a 10.5" rim, but I saw plenty of pictures where that combination looks good and is not stretched.

TireRack delivered the 285's today, but the 245's won't arrive until Wed, and I'll get them mounted then. The sizes are not my first choice, but at least I feel confident that I won't be compromising my AWD system, nor warranty.

What are your thoughts - did I over-think it?

 

[nhcowboy28]

Well, here is my story about buying tires for AWD. I've never had an AWD vehicle before, so I never even thought about keeping the diameters equal front to rear. My car is a 2022 3.3 GT2 AWD.

I bought rims with the following specs:

09.0 x 19 et33
10.5 x 19 et48

..and bought the following tires:

Continental ExtremeContact Sport
255 x 35 x 19 = 26.0" - 775 revs per mile
305 x 30 x 19 = 26.2" - 770 revs per mile

The above specs came from Tire Size Calculator:

Tire Size Calculator

The best tire size calculator. Use our tire size calculator to find tire size specs and suggested tire sizes. Then check prices for all available tire sizes.

tiresize.com

The diameters and revs/mile don't seem like much of a difference, but according to my research reading the Audi, BMW, etc. forums, in order to minimize wear and tear on the transfer case and differential, it is best to keep front/rear diameters to 1% or less. Additionally, I didn't want to mess up my warranty and possibly have a problem due to the mismatched diameters.

Consulting the Tire Size Calculator, I found that the following works with a 305:

265 x 35 x 19 = 26.3" - 767 revs per mile
305 x 30 x 19 = 26.2" - 770 revs per mile

Unfortunately, it has been documented on this forum that a 265 will not fit up front. To confirm, I installed my 255 x 35 on the front and checked the clearance, and there was hardly any clearance, maybe 0.2", between the tire and the shock body, so there was no way a 265 would work - grr. And using a 3mm spacer would push the rim too far out past the fender.

Back to the Tire Size Calculator, all I had to do was buy 295's for the rear:

255 x 35 x 19 = 26.0" - 775 revs per mile
295 x 30 x 19 = 26.0" - 777 revs per mile

That combination is perfect!

But, problems again - Continental does not offer a 295 x 30 x 19 ExtremeContact Sport tire - what's up with that?

I could have bought Michelins, etc. in that size, but since I live in Wisconsin which has colder temperatures in spring and fall, my first choice was to run all-season tires, but there are no 305 19's and why I initially went with UHP Summers.

Finally, I settled on the following all season:

Continental ExtremeContact DWS 06 Plus
245 x 35 x 19 = 25.8" - 784 revs per mile
285 x 30 x 19 = 25.7" - 784 revs per mile

I was concerned that a 285 would be stretched on a 10.5" rim, but I saw plenty of pictures where that combination looks good and is not stretched.

TireRack delivered the 285's today, but the 245's won't arrive until Wed, and I'll get them mounted then. The sizes are not my first choice, but at least I feel confident that I won't be compromising my AWD system, nor warranty.

What are your thoughts - did I over-think it?

Merlin… is that you masquerading as someone else?

 

[D.J.]

What are your thoughts - did I over-think it?

Initially, you under thunk it.
Finally, you over thought it.

Why would you think 285's (11.2") would be "stretched" on a 10.5" rim.

 

[SRV]

Why would you think 285's (11.2") would be "stretched" on a 10.5" rim.

Others have posted the 285 was stretched on a 10.5.

View attachment 68901

Nice chart - thanks!