245/35/19 vs 245/40/19: Sidewall and offset questions

[mrodrig2]

I have been recommended two different tire sizes:1) 245/35/19: 3.4in sidewall, more brands available, +12 rev/mi over stock size2) 245/40/19: 3.9in sidewall, fewer brand choices, -16 rev/mi under stock size

Is the extra 0.5in of sidewall enough to make the ride more comfortable or help prevent blowouts or wheel damage? Is it worth an extra $10-15/tire and limiting my purchase options?

Bonus question:Will I need a small spacer? Going from 16x7 with +35? (stock 08 Altima 2.5, not sure of exact offset) to 19x8 +50 (stock m35/45 sport).

Any advice is appreciated.

[Rex]

If your "location" is accurate, I expect the roads in your area suffer the same winter effects we do here in Ohio.

That said every bit of sidewall helps (ride, blowouts, bent wheels, etc), but you want to be careful not to throw your speedometer too far off. It's part of the "cost" of running larger wheels.

I'm pretty sure running the M45 sport wheels on an Altima Coupe will result in a slightly (more) sunken wheel. A spacer can solve that, but not everyone agrees on the idea of spacers.

Have you looked at the 19" G35 Coupe wheels?

[mrodrig2]

I currently live in WI and spend about 1/3 of the year in Chicago and Indiana due to family and work, so yes poor road conditions are a concern. It sounds like I should try to maximize my sidewall then.

I didn't look too far into getting G35 wheels because I thought they were staggered for RWD and because of high price. Which 19" G35 coupe wheels do you have in mind - the Ray's with the wide split 5-spoke or the 6 spoke ones?


Modified by mrodrig2 at 1:11 PM 12/9/2008

[Rex]

Yes, run as much side wall as you can.

You're right the G35 forged 19's (the split 5 spoke deign) are staggered F/R widths. That's not the "best" thing to do on a FWD car, but there's no real danger in doing so. The down side is not being able to rotate the tires on the wheels ... you can run the same size tires on all 4 wheels.

Either way, I have a set w/TPMS that are in pretty good condition I was looking to sell for ~$750. I have the stock G35 tires as well. Some of the AC guys are running staggered set ups.

All 4

Wheel 1

Wheel 1 scuff

Wheel 2

Wheels 2 Worst curbage

Wheel 2 scuff

Wheel 3

Wheel 3 scuff

Wheel 4

Wheel 4 scuff

They're not "perfect", but in pretty good condition. Let me know if you want any additional pictures.

[mrodrig2]

I'd have to think about that and see if I could sell the m45 wheels beforehand.

If I were to get spacers, do you just get a spacer that is the width of the difference? For example, if stock is +35 and the new wheels are +50, I'd need a 15mm spacer. Is that correct?

[Rex]

I'd have to think about that and see if I could sell the m45 wheels beforehand.

If I were to get spacers, do you just get a spacer that is the width of the difference? For example, if stock is +35 and the new wheels are +50, I'd need a 15mm spacer. Is that correct?

That would work if both wheels were the exact same width, IIRC that's not the case here.

There's a few tools to help you understand how much the inner and outer clearance changes. Try this one. Using that it says the outer edge will only be 2mm farther out (and 28mm less inner clearance), but if you look at your current set up, your tires are "sunken", so you can use spacers to move everything out.

To correct my earlier statement, the new set up will not "look" any more sunken than your current set up, but may not clear the suspension on the "inside".

Looking through some of the Altima Coupe threads, there is a guy using M35/45 Sport wheels. Here's his thread, He doesn't mention spacers, but it might be worth asking him??

Hope all this helps, and sorry for any confusion.