this may have been answered time and time again, but a quick search yielded nothing thus far.

i have the stock 18's on my 07 Z. i was wondering what would be the best idea from the performance aspect. 18's up front and 19's rear or 19s all around? is there a performance difference with having bigger rims in back?

thanks and sorry for being such a n00b.

jim

 

Yes, the black makes all the difference.

 

They make better performing/stickier comps for 18's. So if you are more performance driven, then the 18" wheel is for you.

 

They do have a lot of different tires in 19" sizes as well, but there are a lot more in 18" sizes.

When comparing the two, you cant just compare them in sizes. It certainly makes a difference as to what wheels you are comparing. If you are considering a pair of 19" RPF1's vs a set of 18" ADR M-sports, then the 19" wheels would be better. It all depends on how much money you have, and what you are going for.

 

18" tires are cheaper so if a budget is something important then go 18". i have 19" but plan to get some 18's for track sooner or later and I can get some nice compounds for a decent price instead of paying up the *** for 19" compounds.

 

 

Hence, the need for a longer search young grasshopper...

 

If you're going 19's, diameter wise, you need to get tires that are similar to your factory tires in height. the best setup being 245/35 up front and 275/35 in the rear. Then go for lightweight wheels, work, volks, racing hart if your wallet allows you.

 

What are the "stock" size tires for the 18s ??

 

Well, since you said best for performance, I'd say 17" wheels will give you best speed/traction combo. I know....not the most popular opinion here but it's the truth, all things being equal. You can easily obtain a ridiculously light set of forged 17s that will give you enough width to put good set of rubber. Difference in sidewall flex with good tires between 17s and 18s will be insignificant and your rotational inertia will yield big gains. For best results, you want a fine balance between width of the tire, width of the wheel and their combined overall weight. Going with 305s will not yield best results.

If you're concerned about looks to some degree, well, in that case, you probably will want 18s. Most people here prefer 18s over 17s for estetics so that may be your best bet.

If cost is not an issue, just buy magnesium wheels. Cost is usually a factor with everybody. Some are just willing to spend more than other. So.....what do you want to do?

 

i think its 235/40/18 up front and 255/40/18 in the rear, i will double check on my window sticker though, i could be wrong.

all - thanks for the replies

ziggy - thanks for the info. i do like the look of bigger wheels, so 17s are out of the question. ultra-light wheels are also not going to work since i drive so much and its usually on crappy roads, i dont want to have to fix bends all the time. i guess i was just asking if there was a reason that people have 19's in the rear with 18s up front other than it looking cool.

jim

 

stockies are 225/45 and 245/45