Non-Staggered setup for a 2023 G70 3.3T Rear Drive

[ICEGenesis70]

What would the correct sizing be for having the same size wheels and tires (19 inch) front and rear on a 2023 3.3T rear wheel drive (Sport Prestige w/Brembos)? Are there any 19 inch 235 or 245 sizes that would work for both front and rear? If not, how about 225 sizes? I would like to be able to rotate the wheels front to back, so would like to try a square setup once the original rubber wears out. I do not want to go down to 18s.

 

[Volfy]

I do not want to go down to 18s. The tech at the dealer said he thought the brake calipers would be too close to the wheels if I try going down to 18 inch wheels.

Nothing wrong with having your preference. However, 18" wheels have no problem clearing the Brembo calipers. I have 4 sets of 18s; all of them clear with plenty of gap without spacers.

 

[ICEGenesis70]

Nothing wrong with having your preference. However, 18" wheels have no problem clearing the Brembo calipers. I have 4 sets of 18s; all of them clear with plenty of gap without spacers.

Thank you.

 

[ICEGenesis70]

Okay, but what aspect ratio will work on 245 or 235 tires? That’s my main question. I will probably buy new wheels, but I am just trying to figure out rubber sizes that will work on the 2023 Sport prestige without using spacers.

 

[Volfy]

Are you going to remount the tires back and forth between the front and rear wheels every time you rotate the tires? The staggered wheels cannot be rotated front to rear.

 

[ICEGenesis70]

Are you going to remount the tires back and forth between the front and rear wheels every time you rotate the tires? The staggered wheels cannot be rotated front to rear.

No. My plan is to buy a new set of wheels, all the same size. That would allow me to rotate front to back without having to remount the rubber. I want to move away from the staggered setup eventually, if possible.

 

[Jlapaglia]

I would check out the wheel offsets on tire rack. I think you need that first before figuring out tires. They will give you an idea on what fits. I run 225/45/18 all around for winter tires. You could buy two oem front wheels and run 225 all around and keep a stock look. I would just keep in mind that the smaller width rear tire may reduce grip quite a bit depending on how aggressive you drive.

 

[ICEGenesis70]

I would check out the wheel offsets on tire rack. I think you need that first before figuring out tires. They will give you an idea on what fits. I run 225/45/18 all around for winter tires. You could buy two oem front wheels and run 225 all around and keep a stock look. I would just keep in mind that the smaller width rear tire may reduce grip quite a bit depending on how aggressive you drive.

Okay, thanks for your reply.

 

[ICEGenesis70]

The OEM tires on my 2023 Sport Prestige are Front: 225 40-19; Rear 255 35-19. Trying to figure out if I can do a non-staggered set up with 235 or 245 tires

 

[Jlapaglia]

This is the calculator I used when seeing about different tire sizes and overall size differences. Idk how our mph or odometer calculates and whether or not a different overall diameter will impact those. Looks like a 235/40 or 245/35 wouldn’t change much assuming there isn’t a fitment issue.

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

I just built a set on tire rack. 19x8 wheels +35 offset and 245/35 tires. Seems to allow it.

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[ICEGenesis70]

This is the calculator I used when seeing about different tire sizes and overall size differences. Idk how our mph or odometer calculates and whether or not a different overall diameter will impact those. Looks like a 235/40 or 245/35 wouldn’t change much assuming there isn’t a fitment issue.

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

I just built a set on tire rack. 19x8 wheels +35 offset and 245/35 tires. Seems to allow it.

Thank you. I’ll go back into Tire Rack later today.

 

[Volfy]

No. My plan is to buy a new set of wheels, all the same size. That would allow me to rotate front to back without having to remount the rubber. I want to move away from the staggered setup eventually, if possible.

Got it. That opens up a lot of possibilities.

Since yours is a 3.3T, I would go no smaller than 245 for power handling, which is the whole reason for the staggered setup with the larger 255 in the rear. 255/35R19 on 19x8.5 would be safest bet for what you want to accomplish. Rolling diameter will be about the same as OEM, so your speedometer calibration won't change. Make sure to keep offset as close to the front OEM 34mm as possible. Rear offset is not as critical, since scrub radius being off a bit won't affect steering sensitivity as much as the front axle.

From there, you can play with the tire sizing a bit, if you are so inclined. A lot depends on to what end you want to tilt, performance, ride quality, NVH, etc. For example, 255/40R19 would have slightly taller sidewall for better ride quality. Rolling diameter would be about 3.5% larger, so your speedometer would read lower by about that much. Not a huge deal as long as you keep that in mind while driving. 245/40R19 would also work well.

Having wider tire up front will increase steering effort a bit, although likely not something you'll notice in everyday driving. We run 255/40R18 square on our G70, and I really cannot tell much of a difference in street driving. At the track, yes. Not objectionable and almost preferrable in that environment.

With wider tires up front, road noise will also likely be a bit higher, though a lot of that depends on the tire you chose.

 

[ICEGenesis70]

Got it. That opens up a lot of possibilities.

Since yours is a 3.3T, I would go no smaller than 245 for power handling, which is the whole reason for the staggered setup with the larger 255 in the rear. 255/35R19 on 19x8.5 would be safest bet for what you want to accomplish. Rolling diameter will be about the same as OEM, so your speedometer calibration won't change. Make sure to keep offset as close to the front OEM 34mm as possible. Rear offset is not as critical, since scrub radius being off a bit won't affect steering sensitivity as much as the front axle.

From there, you can play with the tire sizing a bit, if you are so inclined. A lot depends on to what end you want to tilt, performance, ride quality, NVH, etc. For example, 255/40R19 would have slightly taller sidewall for better ride quality. Rolling diameter would be about 3.5% larger, so your speedometer would read lower by about that much. Not a huge deal as long as you keep that in mind while driving.

Having 255 up front will increase steering effort a bit, although likely not something you'll notice in everyday driving. We run 255/40R18 square on our G70, and I really cannot tell much of a difference in street driving. At the track, yes.

With wider tires up front, road noise will also likely be a bit higher, though a lot of that depends on the tire you chose.

Fantastic! These are exactly the answers and parameters I was looking for. Thank you so much!

 

[JCtx]

The OEM tires on my 2023 Sport Prestige are Front: 225 40-19; Rear 255 35-19. Trying to figure out if I can do a non-staggered set up with 235 or 245 tires

The problem with OEM wheels is the rear are wider (by 1/2", I think -8.0 vs 8.5 wide), so I wouldn't use them for a square setup... although you could. And the front would be a problem way before the rear, so watch out the offset. And yes, you'd hear more noise too, especially with summer tires. To be honest, with the money you'd have to spend on that, just keep the stock sizes, and change tires a bit earlier than if you were to rotate them. It should be cheaper too, unless you plan to keep the car a million miles. Ha ha. But to each his own, of course . Good luck.

 

[ICEGenesis70]

Got it. That opens up a lot of possibilities.

Since yours is a 3.3T, I would go no smaller than 245 for power handling, which is the whole reason for the staggered setup with the larger 255 in the rear. 255/35R19 on 19x8.5 would be safest bet for what you want to accomplish. Rolling diameter will be about the same as OEM, so your speedometer calibration won't change. Make sure to keep offset as close to the front OEM 34mm as possible. Rear offset is not as critical, since scrub radius being off a bit won't affect steering sensitivity as much as the front axle.

From there, you can play with the tire sizing a bit, if you are so inclined. A lot depends on to what end you want to tilt, performance, ride quality, NVH, etc. For example, 255/40R19 would have slightly taller sidewall for better ride quality. Rolling diameter would be about 3.5% larger, so your speedometer would read lower by about that much. Not a huge deal as long as you keep that in mind while driving. 245/40R19 would also work well.

Having wider tire up front will increase steering effort a bit, although likely not something you'll notice in everyday driving. We run 255/40R18 square on our G70, and I really cannot tell much of a difference in street driving. At the track, yes. Not objectionable and almost preferrable in that environment.

With wider tires up front, road noise will also likely be a bit higher, though a lot of that depends on the tire you chose.

@Volfy: Thanks again for your answer. I have done a little more looking at the issues, and found the tiresize.com calculator, which is an amazing resource. It let me do a comparison of the original tire sizes with a hypothetical 245/40R19 tire. See attached images.

So, would a 245/40R19 work in a square setup? The diameter is 0.6 inch larger than the original front tire, and 0.7 inch larger than the original rear tire.
If I were to go with the 245/40R19 square setup, would you recommend an 8.0 inch wide wheel, or an 8.5 inch wide wheel?
Would I be able to pull this off without using spacers, or would using spacers be better?
I'm not opposed to going with a 255/35R19 or 255/40R18 square setup as well (which would keep the diameter at exactly 26 inches), but I am thinking I should probably get used to driving the car with the staggered setup before moving to a square set up. My understanding from other sources is that a square setup can increase the tendency of the car's tail to step out somewhat, and that is consistent with your answer in another thread that going to a square set up with 255s up front decreases the car's initial understeer on initial turn in.

Thanks again for all your time and help.

 

[Volfy]

@Volfy: Thanks again for your answer. I have done a little more looking at the issues, and found the tiresize.com calculator, which is an amazing resource. It let me do a comparison of the original tire sizes with a hypothetical 245/40R19 tire. See attached images.

So, would a 245/40R19 work in a square setup? The diameter is 0.6 inch larger than the original front tire, and 0.7 inch larger than the original rear tire.
If I were to go with the 245/40R19 square setup, would you recommend an 8.0 inch wide wheel, or an 8.5 inch wide wheel?
Would I be able to pull this off without using spacers, or would using spacers be better?
I'm not opposed to going with a 255/35R19 or 255/40R18 square setup as well (which would keep the diameter at exactly 26 inches), but I am thinking I should probably get used to driving the car with the staggered setup before moving to a square set up. My understanding from other sources is that a square setup can increase the tendency of the car's tail to step out somewhat, and that is consistent with your answer in another thread that going to a square set up with 255s up front decreases the car's initial understeer on initial turn in.

Thanks again for all your time and help.

245/40R19 should do fine in a square setup. As you have found out, the rolling diameter will be off by less than 3%. Not enough to cause clearance issues. Speedometer calibration should still be very usable, as most mfrs tend to calibrate their speedo to be somewhat less than actual speed, so the slightly larger diameter will offset that.

Ideal rim width for 245/40R19 is 8.5", but it should work well on 8" wheels. Which you choose depends on your priority. On the narrower rim, you'd be trading sidewall stiffness for tire compliance, which means trading handling sharpness for better ride quality. Difference is subtle and probably only noticeable if you drive two sets of tire/wheels back to back, which we do with our 4 sets. However, the type of tire you choose will also influence those two factors. For example, going with an ultra-high performance Summer tire will likely be sharper handling than a grand touring all season tire.

In your case, I would recommend going with 8.5, which will give you the option later on for trying 255/35R19. Most tire mfrs list 8.5 as the lower limit for rim width in that tire size. Need for spacers depends on the offset of the wheel you choose. As a rule, always stay as close as you can to the stock 34mm at the front. Rear isn't as sensitive, so you can afford to be less than the stock offset. Just don't nuts. So, if you go with a 19x8.5 ET35, then no spacer necessary. If it's ET40, you can correct with a 5mm spacer up front.

As for driving characteristics of staggered vs. squared setup, you'd really only notice it when you push the car hard, like AutoX and track day. On public roads in everyday driving, you likely won't notice much difference. Also, reduced tendency for understeer on turn in does not mean the car has a loose rear end. Set up correctly, a square setup should make the G70 more neutral steering. To get the tail to break into a drift, you'd have to drive like a mad monkey, with TC/SC turned completely off. And if that's your thing, then it might not be such a bad thing.

 

[ICEGenesis70]

245/40R19 should do fine in a square setup. As you have found out, the rolling diameter will be off by less than 3%. Not enough to cause clearance issues. Speedometer calibration should still be very usable, as most mfrs tend to calibrate their speedo to be somewhat less than actual speed, so the slightly larger diameter will offset that.

Ideal rim width for 245/40R19 is 8.5", but it should work well on 8" wheels. Which you choose depends on your priority. On the narrower rim, you'd be trading sidewall stiffness for tire compliance, which means trading handling sharpness for better ride quality. Difference is subtle and probably only noticeable if you drive two sets of tire/wheels back to back, which we do with our 4 sets. However, the type of tire you choose will also influence those two factors. For example, going with an ultra-high performance Summer tire will likely be sharper handling than a grand touring all season tire.

In your case, I would recommend going with 8.5, which will give you the option later on for trying 255/35R19. Most tire mfrs list 8.5 as the lower limit for rim width in that tire size. Need for spacers depends on the offset of the wheel you choose. As a rule, always stay as close as you can to the stock 34mm at the front. Rear isn't as sensitive, so you can afford to be less than the stock offset. Just don't nuts. So, if you go with a 19x8.5 ET35, then no spacer necessary. If it's ET40, you can correct with a 5mm spacer up front.

As for driving characteristics of staggered vs. squared setup, you'd really only notice it when you push the car hard, like AutoX and track day. On public roads in everyday driving, you likely won't notice much difference. Also, reduced tendency for understeer on turn in does not mean the car has a loose rear end. Set up correctly, a square setup should make the G70 more neutral steering. To get the tail to break into a drift, you'd have to drive like a mad monkey, with TC/SC turned completely off. And if that's your thing, then it might not be such a bad thing.

Thanx!

 

[ICEGenesis70]

245/40R19 should do fine in a square setup. As you have found out, the rolling diameter will be off by less than 3%. Not enough to cause clearance issues. Speedometer calibration should still be very usable, as most mfrs tend to calibrate their speedo to be somewhat less than actual speed, so the slightly larger diameter will offset that.

Ideal rim width for 245/40R19 is 8.5", but it should work well on 8" wheels. Which you choose depends on your priority. On the narrower rim, you'd be trading sidewall stiffness for tire compliance, which means trading handling sharpness for better ride quality. Difference is subtle and probably only noticeable if you drive two sets of tire/wheels back to back, which we do with our 4 sets. However, the type of tire you choose will also influence those two factors. For example, going with an ultra-high performance Summer tire will likely be sharper handling than a grand touring all season tire.

In your case, I would recommend going with 8.5, which will give you the option later on for trying 255/35R19. Most tire mfrs list 8.5 as the lower limit for rim width in that tire size. Need for spacers depends on the offset of the wheel you choose. As a rule, always stay as close as you can to the stock 34mm at the front. Rear isn't as sensitive, so you can afford to be less than the stock offset. Just don't nuts. So, if you go with a 19x8.5 ET35, then no spacer necessary. If it's ET40, you can correct with a 5mm spacer up front.

As for driving characteristics of staggered vs. squared setup, you'd really only notice it when you push the car hard, like AutoX and track day. On public roads in everyday driving, you likely won't notice much difference. Also, reduced tendency for understeer on turn in does not mean the car has a loose rear end. Set up correctly, a square setup should make the G70 more neutral steering. To get the tail to break into a drift, you'd have to drive like a mad monkey, with TC/SC turned completely off. And if that's your thing, then it might not be such a bad thing.

Hello again. Thanks again for your previous answers. So, I am getting close to switching over to a square setup, and using all-season tires, since weather is getting colder. I am keeping in mind your previous advice to stay as close as possible to the wheel offset as possible, especially for the front of the car. Last night, I found a website, wheel-size.com, that lists the OEM wheel specs for my car, a 2023 3.3T. When I go to the square setup, I am planning on using 255 35R 19 all around.

Wheel-size.com website shows the OEM wheel sizes as follows:
Front: 8J X 19 ET 34
Rear: 8.5J X 19 ET 46.5

So, I am assuming that the ET 34 is the offset for the front wheel, and the ET 46.5 is the offset for the back wheel?

The website shows the offset range for the front as 32 to 36 mm
It shows the offset range for the rear as 44.5 to 48.5 mm

Also, in one of the articles I have read, it said that going to a wider wheel could change the required offset. So my question is the following. Since the wheel width difference between the front and the rear wheels is 0.5 inches (12.7 mm), and the difference in the ET offset value for the front and rear wheels is 12.5 mm (34 mm vs. 46.5 mm), is the 12.5 difference in the ET offset value simply due to the fact that the rear wheel is 12.7 mm wider?

And if that is the case, would it be correct for me to buy wheels for a square setup that have a listed offset of 46.5 mm for the front and rear? Rather than buying wheels that have a listed offset of 34 mm? Or is the calculation more nuanced than that?

Thanks for your input. I really appreciate your time.

 

[Volfy]

Hello again. Thanks again for your previous answers. So, I am getting close to switching over to a square setup, and using all-season tires, since weather is getting colder. I am keeping in mind your previous advice to stay as close as possible to the wheel offset as possible, especially for the front of the car. Last night, I found a website, wheel-size.com, that lists the OEM wheel specs for my car, a 2023 3.3T. When I go to the square setup, I am planning on using 255 35R 19 all around.

Wheel-size.com website shows the OEM wheel sizes as follows:
Front: 8J X 19 ET 34
Rear: 8.5J X 19 ET 46.5

So, I am assuming that the ET 34 is the offset for the front wheel, and the ET 46.5 is the offset for the back wheel?

The website shows the offset range for the front as 32 to 36 mm
It shows the offset range for the rear as 44.5 to 48.5 mm

Also, in one of the articles I have read, it said that going to a wider wheel could change the required offset. So my question is the following. Since the wheel width difference between the front and the rear wheels is 0.5 inches (12.7 mm), and the difference in the ET offset value for the front and rear wheels is 12.5 mm (34 mm vs. 46.5 mm), is the 12.5 difference in the ET offset value simply due to the fact that the rear wheel is 12.7 mm wider?

And if that is the case, would it be correct for me to buy wheels for a square setup that have a listed offset of 46.5 mm for the front and rear? Rather than buying wheels that have a listed offset of 34 mm? Or is the calculation more nuanced than that?

Thanks for your input. I really appreciate your time.

Wheel offset on the front axle is far more critical because, unlike the rears, the front wheels do steer. When the front wheels turn side to side, camber and the other suspension geometry also change. Not only do the front wheels do all (or most of) the steering, but the front wheels also sustain the majority of the braking force. Keeping the front scrub radius as close to stock geometry as possible will ensure there are no mid-corner bump steers and other instability issues. Scrub radius is a rather abstract parameter for most folks not well-versed in ground vehicle dynamics to grasp, which is why most drivers are oblivious to the concept. Instead, most just zone in on simplistic visual cues like "stance" and "poke", etc.

It doesn't help matters when lots of folks drive around on thick spacers and seem to suffer no ill effects. Well... if you are just going down the hwy straight... yeah, everything might seem hunky dory, but... hit a puddle of water with one of the front wheels while making a turn at speed... well, that's when you find out why installing 20mm spacers might not be such a hot idea. that is just one example. Then again... if something were to happen and the car ends up in the weeds or guard rails, would the driver have the presence of mind to know what caused it? Probably not.

Google search for SCRUB RADIUS to learn more about it. There are quite a few good articles and vids. Jason explains it quite well here:

Okay... so what about the rears, you ask? Because arguably the main job of the rear wheels in a RWD car is propulsion, the toe angle of the driven wheel actually contributes more to vehicle stability than scrub radius. On a FWD car, that job falls again on the front wheels, making front suspension geometry even more critical to get right. On a RWD, as long as the toe-in is set properly, wheel offset can vary some. The fact that the rear suspension is multi-link, instead of the front MacPherson strut, also allows the rear geometry to vary less when the suspension articulates up-n-down

The GT-Line comes with square setup, with 34mm offset 18x8 all around. So factory engineers obviously agree.

in one of the articles I have read, it said that going to a wider wheel could change the required offset.

I'd take exception to that statement. As long as clearances allow for a wider wheel to maintain the same offset, it is ALWAYS better to keep the front wheel offset as close to stock as possible. Obviously, if you want to install a 19x9.5 on the front, then there is no way that's gonna happen without reducing the wheel offset. The question you first have to ask is: "what advantage(s) do 19x9.5 wheels up front afford the car, and do those advantage(s) outweigh the downsides of more unsprung weight, higher rotational inertia and substantially out-of-spec scrub radius?"

Can't speak for everyone, but if I have trouble answering that to my own satisfaction, perhaps it is best I refrain from doing something that might produce outcomes I can neither understand nor predict.

 

[Volfy]

All that jibber jabber and I forgot to mention the actual offset I'd recommend.

So, because the the factory square setup has 18x8 ET34 all around, just about anything close to that is fine. The same website you mentioned also recommends offset range in the 32-36mm. My TFR 18x8.5 has an offset of 38mm, which actually works out quite well. On the front, I can run them with 5mm hubcentric spacer, which corrects the offset to 33mm. In the rear, 38 is between factory GT-Line square setup's 34mm and GT staggered setup's 46.5mm. The same would work with 19x8.5 aftermarket wheels up to 40mm offset.

Just as an example, in the same Enkei TFR series, 19x8.5 come in either ET35 or ET45. I would pick the 35 and bolt on as is, no spacers. 45 is meant more for FWD fitment. On the Stinger, ET45 would be perfect for the rear but front would need a spacer around 8-12mm thick, which is a problem. You would most likely have to replace the OEM studs with longer ones. A bit too much work IMO.

In any case, get the alignment adjusted afterwards. Highly recommend a lifetime alignment and have it checked yearly or whenever you think it's necessary.