275/40/18 - Will it fit in the front

[e36bmer]

So, I've been trying to get away from my 666m and put on some 18s. For some reason 513m seem to be in low supply, so I thought I might toss some street rubber on my old e46 track wheels. I have a square Apex SM-10 18x10" et 25 setup with 265/35/18 from my e46. However, I really want a thicker sidewall to help cushion the ride and this size puts me at some economical tire options with the Indy 500 since I drive a lot. Also, I have the KW set as high as they'll go and with those 35 profile tires, the car is too low to be practical in Houston.

Has anyone tried or know if a 275/40/18 will fit up front? I feel like there is a lot of room from my 265/35/18 now. I'm lowered on KW HAS and I'm willing to find the right spacers or make some minor fender adjustments if needed. I just don't want to buy the tires if they don't fit at all.

Any input is greatly appreciated.

[rx7gslse]

265 40 I’ve been running for years with no issue. Ordered a set of 275 40 rs4s, so I’ll let ya know once they get here!

[erictrainer]

Subscribed... this is the exact setup I want to run...F275/40/18 and R295/40/18 RS4s. I just tried fitting some 275/35/19 RS4s and unfortunately it didn't work out for me. Tried doing it on 10.5et22 wheels. My clearance issue was with the front spring perch...I think the fender would've been fine. Anyhoo here are some pics...I really wanted to try these tires out.

With that said the 275/40/18 is about the same height... I believe the difference comes down to the inner clearance. With HAS in my experience it won't work, but if you're on stock suspension with springs it probably will, or on aftermarket suspension with greater clearance than stock.

[erictrainer]

265/35/19 P4S on 9.5et22 vs 275/35/19 on 10.5et22.

These tires looked so nice on the wheels, I really wanted it to work out!

[JamesGames]

From my experience, 275 works on 9-9.5 inch wheel and not on 10-11'' front. This is only if you are running sizes that are slightly taller than OEM. my 10'' width 275 tire rubbed slightly on the inner fenders on lock.

Example of front 275 with slight overall taller diameter than stock:
275/40/18
275/35/19
275/30/20

Any of these with 10'' wheels that clear most coil perches will slightly rub the fender liners. not a huge deal as they were a slight rub but YMMV. Obviously dependent on different tire brands / types as well.

However, if you run slightly shorter diameter you could probably get away with it.
275/35/18
275/30/19
275/25/20 (hard pass, just run 265/30!)

In 20s, many people run 9.5'' et 22 with 275/30/20s and have no issues.

[JamesGames]

Originally Posted by erictrainer

Subscribed... this is the exact setup I want to run...F275/40/18 and R295/40/18 RS4s. I just tried fitting some 275/35/19 RS4s and unfortunately it didn't work out for me. Tried doing it on 10.5et22 wheels. My clearance issue was with the front spring perch...I think the fender would've been fine. Anyhoo here are some pics...I really wanted to try these tires out.

With that said the 275/40/18 is about the same height... I believe the difference comes down to the inner clearance. With HAS in my experience it won't work, but if you're on stock suspension with springs it probably will, or on aftermarket suspension with greater clearance than stock.

10.5 ET 22 with some coilovers/HAS will hit the perch, especially KW.. I'm running 10'' ET 18 and I have maybe, 5mm of clearance at MOST until I hit my perch. (KW CS 3 way)

[ilia]

I'm interested in running this tire size (RS-4's) on track next year with MPHAS and CG camber plates on 18x10 et 25. Do you guys think it'll fit without spacers? Thanks

[erictrainer]

Originally Posted by ilia

I'm interested in running this tire size (RS-4's) on track next year with MPHAS and CG camber plates on 18x10 et 25. Do you guys think it'll fit without spacers? Thanks

Highly doubt without spacers...I believe it's doable with 2 conditions:
a. Spacers
b. Higher ride height

If you look at my pic had I raised my height about an inch I believe I could've pulled it off... but I did not want to that.

[ilia]

Originally Posted by erictrainer

Highly doubt without spacers...I believe it's doable with 2 conditions:
a. Spacers
b. Higher ride height

If you look at my pic had I raised my height about an inch I believe I could've pulled it off... but I did not want to that.

Thank you