Wheel diameter discrepancy for AWD

[RockyBikeRider]

Hey all,

I couldn’t find a thread discussing this, but please feel free to point me to one if it already exists.

I’m planning on buying the staggered TSW Sprint wheels (19x8.5, 19x9.5) for my AWD. My concern is with tire diameter. I’d like to run 255s front and 275s rear, but there is a 2% difference in diameter. I’m not sure if that would put stress on the AWD system. Does anyone know of official guidance on this issue. I’ve heard of a 3% max diff from stock, but not sure how official that is and whether that applies to both front and back being the same 3% change from stock.

I realize that the system must be able to cope with some difference in diameter front to back (my rear tires are wearing faster ;-), but would love to find an official limit on this diff.

 

[Bear]

What size sidewall are you running on front and rear?

You’ll be fine with 255/35/19 and 275/30/19

 

[RockyBikeRider]

Yeah, those are the tires. According to the site linked below there is a 2% difference in diameter between them.

2017 Kia Stinger 3.3T GT AWD tire sizes (since 4th Quarter 2017 for Europe )

 

[sean888]

Hey all,

I couldn’t find a thread discussing this, but please feel free to point me to one if it already exists.

I’m planning on buying the staggered TSW Sprint wheels (19x8.5, 19x9.5) for my AWD. My concern is with tire diameter. I’d like to run 255s front and 275s rear, but there is a 2% difference in diameter. I’m not sure if that would put stress on the AWD system. Does anyone know of official guidance on this issue. I’ve heard of a 3% max diff from stock, but not sure how official that is and whether that applies to both front and back being the same 3% change from stock.

I realize that the system must be able to cope with some difference in diameter front to back (my rear tires are wearing faster ;-), but would love to find an official limit on this diff.

1. It is not only the AWD system that you need to take into account but the electronic stability control systems as well. Too bigger difference between the front and rear tire diameters will play havoc with the system.

2. KIA has kept the front and rear tire diameters very close on the staggered 19 inch 225/40 Fr and 255/35 Rear tire set up which should be a good indicator and reference on what you need to do. (just a 2 mm difference which is insignificant).

3. The 255 35 19 and 275 30 19 provides too much difference between front and rear tire diameters. Run that if you like but expect problems if you do. With an AWD car I would definitely not be doing this.

4. If you really want the 255 35 19(661 mm diam.) up front you will need a 285 30 19 (655 mm diam.)on the rear which is just a 6 mm difference ( just under 1%) (or go to the 255 on the rear also). With the correct offset wheel a 285 30 19 will fit on the rear. You can run either a 9.5 or 10 inch wheel with that 285 30 19 size. (You will need a 42 offset wheel).

5. The 255 35 19 is still a very wide tire. You will still have the staggered look, because of the wider rear wheel, if you run this 255 tire on the 9.5 inch rear wheels as well and you won't need to worry about tire diameter differences with the AWD or other systems. Nor will you have any issues if you need to bolt on the spare tire at some stage which is also a consideration when changing tire diameters, even more so on an AWD car.

 

[Aqueel94]

1. It is not only the AWD system that you need to take into account but the electronic stability control systems as well. Too bigger difference between the front and rear tire diameters will play havoc with the system.

2. KIA has kept the front and rear tire diameters very close on the staggered 19 inch 225/40 Fr and 255/35 Rear tire set up which should be a good indicator and reference on what you need to do. (just a 2 mm difference which is insignificant).

3. The 255 35 19 and 275 30 19 provides too much difference between front and rear tire diameters. Run that if you like but expect problems if you do. With an AWD car I would definitely not be doing this.

4. If you really want the 255 35 19(661 mm diam.) up front you will need a 285 30 19 (655 mm diam.)on the rear which is just a 6 mm difference ( just under 1%) (or go to the 255 on the rear also). With the correct offset wheel a 285 30 19 will fit on the rear. You can run either a 9.5 or 10 inch wheel with that 285 30 19 size. (You will need a 42 offset wheel).

5. The 255 35 19 is still a very wide tire. You will still have the staggered look, because of the wider rear wheel, if you run this 255 tire on the 9.5 inch rear wheels as well and you won't need to worry about tire diameter differences with the AWD or other systems. Nor will you have any issues if you need to bolt on the spare tire at some stage which is also a consideration when changing tire diameters, even more so on an AWD car.

Would 245/35/19 Front and 285/30/19 Rear work? i have seen some setups online with people running that but was not sure if it would impact the AWD and Odometer.

 

[Snow_White]

I have just ordered a set of new tires that employ a staggered setup on the stock 19" wheels. The vendor says the tires possibly won't fit, but they always err on the side of caution. There is a VERY slight stretch on the back tires at 255 from factory, and a significant stretch on the front tires at 225.

F - 245/40R19
R - 275/35R19

They hopefully go on without any issues, the preferred worst case would be the addition of 5mm spacers.

This option has 0.5% difference in sizing between front and rear, and would be typically considered the safe zone.

In actuality, the final sizing is only 1/2" +/- taller and 3/4" +/- wider than the stock tires. This equates to only 1/4" radius increase and 3/8" increase per side of the wheel.

I've searched high and low for the answers to the "biggest tires on stock wheels" and came up with mostly theory, no one appears to have performed the dive in method.


------- In saying all of this, I have had major issues on an AWD Jeep SRT8 that had just under 3% discrepancy, and was told by the DEALER it should be fine. I ended up needing to purchase new rear tires on a Jeep that had week old tires i was stuck with after. Since then I have always tried to stay 1% or less in the delta between front and rear. This is why for the winter tires listed above I maintained the sizing I did.---------

 

[OxKing]

Hey,
My 2018 GT2 AWD came with the 18" wheels 225/45R18 tire squared setup and I'm thinking of changing to staggered, but I have several questions. Is there any pros beside the looks when going staggered and any cons beside not being able to fully rotate your tires? Will I have to change my wheel size to 19" or can I stay with 18"? If I go with the stock staggered setup from the RWD version with 225s front and 255s rear, is there anything extra I will have to do or will the electronic stability control, AWD system and Odometer be okey with no adjustments need?

 

[SKStinger]

I have just ordered a set of new tires that employ a staggered setup on the stock 19" wheels. The vendor says the tires possibly won't fit, but they always err on the side of caution. There is a VERY slight stretch on the back tires at 255 from factory, and a significant stretch on the front tires at 225.

F - 245/40R19
R - 275/35R19

They hopefully go on without any issues, the preferred worst case would be the addition of 5mm spacers.

This option has 0.5% difference in sizing between front and rear, and would be typically considered the safe zone.

In actuality, the final sizing is only 1/2" +/- taller and 3/4" +/- wider than the stock tires. This equates to only 1/4" radius increase and 3/8" increase per side of the wheel.

I've searched high and low for the answers to the "biggest tires on stock wheels" and came up with mostly theory, no one appears to have performed the dive in method.


------- In saying all of this, I have had major issues on an AWD Jeep SRT8 that had just under 3% discrepancy, and was told by the DEALER it should be fine. I ended up needing to purchase new rear tires on a Jeep that had week old tires i was stuck with after. Since then I have always tried to stay 1% or less in the delta between front and rear. This is why for the winter tires listed above I maintained the sizing I did.---------

That is the size i'm moving to next as well.

 

[MerlintheMad]

Hey,
My 2018 GT2 AWD came with the 18" wheels 225/45R18 tire squared setup and I'm thinking of changing to staggered, but I have several questions. Is there any pros beside the looks when going staggered and any cons beside not being able to fully rotate your tires? Will I have to change my wheel size to 19" or can I stay with 18"? If I go with the stock staggered setup from the RWD version with 225s front and 255s rear, is there anything extra I will have to do or will the electronic stability control, AWD system and Odometer be okey with no adjustments need?

OE staggered 19" is not only a "RWD version". Many AWD come with the 19" staggered setup (mine, for instance). So, you'll be fine. (the limited top speed of 140 MPH is yours for the duration, though; changing to 19" wheels only changes the look slightly, not the speed limiter; I suppose that your handling should be noticeably better with summer rubber, and wider in the rear)

 

[Ohiocruiser]

225/45-18 front, and 255/40-18 rear. They are exact the same diameter tires.