Which front tire with 305/45/17 rear?

[78novacaine]

Got new wheels on order (17×10 and 18×8) and needing some input on which front tire to go with. Car is a 2014 a6 SS making around 600 whp (d1sc). Already have the 305/45/17's on their way for the rear, but I'm torn between 245/50/18 and 255/45/18 for the front. The 245's are only 1/5" shorter than the rears so I'm guessing those would be best, but I would like to run the shorter (27") tire up front if it won't cause the electronic nannies to have a hissy fit with a 4/5" difference front to rear. Car is mostly street driven so I want to maintain as much handling/braking capacity as possible, hence no runners up front. TIA.

[SS_Dave]

My understanding is more than 60 revolutions difference and you have a problem. Somewhere I thought I saw more than a half inch in height was an issue too, but I can't say for sure. What you spec'd is 20 revolutions and .8 inches in height. So, I think you're ok.

[78novacaine]

Originally Posted by SS_Dave

My understanding is more than 60 revolutions difference and you have a problem. Somewhere I thought I saw more than a half inch in height was an issue too, but I can't say for sure. What you spec'd is 20 revolutions and .8 inches in height. So, I think you're ok.

I ended up finding something in the middle, 235/50/18 which comes out to a difference of 0.5" and 14 revs/mile. Should have them mounted by the end of the week and report back.

[78novacaine]

Only put about 30 miles on the setup, but so far so good. Absolutely loving the stance (and the newfound grip of course).

[chuckie669]

Looks good. Did you have to modify the rear at all. I was looking at the 17x10 ventura 5 and the guide on weld site said stock or lowered needed to modify lca.

What tire did you end up with up front?

I guess going 28.7 diameter rear to 27.8 you just let the speedo difference be?

[78novacaine]

Originally Posted by chuckie669

Looks good. Did you have to modify the rear at all. I was looking at the 17x10 ventura 5 and the guide on weld site said stock or lowered needed to modify lca.

What tire did you end up with up front?

I guess going 28.7 diameter rear to 27.8 you just let the speedo difference be?

I had to zip tie the parking brake line on both sides as it was rubbing the wheels, other than that no issues so far. The car is lowered on BMR springs but still has stock suspension otherwise to the best of my knowledge.

I don't remember the brand for sure, I think they are called Roadhugger Ultra or something like that. They were the second cheapest Z rated tire Discount had available in a 235/50/18.

Yeah, I'm not worried about the speedo being a couple mph off. As long as the electronic nannies don't act up and shift points stay good then I'm happy, and so far so good on those fronts.

[Munz91]

Originally Posted by 78novacaine

I had to zip tie the parking brake line on both sides as it was rubbing the wheels, other than that no issues so far. The car is lowered on BMR springs but still has stock suspension otherwise to the best of my knowledge.

I don't remember the brand for sure, I think they are called Roadhugger Ultra or something like that. They were the second cheapest Z rated tire Discount had available in a 235/50/18.

Yeah, I'm not worried about the speedo being a couple mph off. As long as the electronic nannies don't act up and shift points stay good then I'm happy, and so far so good on those fronts.

I want your exact set up. I have 1” rear, 1.25” front BMR springs going on next week. I keep reading that people had to notch their stock LCA, lowered with 17” wheels. But I’m reading that you didn’t have an issue with this?