A pcmforless gives better performance, going from 33s (285s) to 35s (315s) lowers performance. What I'm not sure of is if they basically offset each other or if one has more effect than the other. I will eventually get an PCMforless, and I'd like to step up tire size a bit, but not if the end result will be lower performance than stock. I've driven some long highway hills in the H3 where it struggled a bit and I had to drive slower to keep the rpms reasonable (~60mph instead of ~72mph), the H3t seems like it will be a touch worse.

I did do a search, but can't really find an answer. Plenty of "you'll be fine" and "35s are worth it" type answers, but lots of hills here in UT and I don't want to make things any worse for my I5 H3t with automatic. Lots of mpg related stuff, but I'm not worried about mpg. Mainly just interested in highway merging, big long hills, that kind of thing. I may also try to find a tire somewhere between 285s and 315s, but I don't think there are very many options. I do realize weight can vary, but any personal experiences would be great.

 

I live in mid-south Indiana and it is not all flat here.I had an 07 Adventure with 285s and it responded well. When I purchased my 08 Alpha it had 265s and I put 285s on it and nothing changed power, mpg, just the stance.I hope this will help a little and I would assume you will get more reply's.:

 

As you stated. 285s to 315s you will lose some power. The PCM for less with an CAI will bering you back to about stock performance amybe a little better. The best part aobut it is that the PCM for less tune will adjust your trans settings for those hills. Contact marchall @ PCMfor less and ask him any question you want. He was very helpful and took great care of me!

 

Perfect, just the answer I was hoping for. I know about the tranny settings, and I plan to buy a PCMforless either way, just wanting to know if I can plan for 35s or if I should stick with 33s.