Could use some opinions; my size isn't listed on the chart.

[Marineguy]

So the old Envoy is getting some upgrades over the next few days: a BDS 2" lift, Mark's 1.5" spacers, and finally (and most importantly) some new tires. The only question is what size?

As a Denali, it has the 245/60R18s on it. Last time I went with the LTX M/S, even though they had an even less-aggressive tread than the usual LTX M/S tires in higher profile series. So now that they're worn out and no longer available, I'm doing a lot of the things I've wanted to do for years to make this vehicle into the truck it should have been when they put it together in Ohio.

I'm looking at Firestone Destination ATs.

At first I was thinking of going with 265/60R18s (30.5"), mainly out of fear that anything bigger would require me to trim the body, but now I'm thinking I can get away with 265/65R18s (31.5"). But what about 255/70R18s (32")? Think they'd fit?

I never was particularly fond of the Denali chrome rims, but don't want to incurr yet another expense right now and also don't really want to mess with the TPMS. So I'll be keeping them. They are kind of nice, anyway. They're 18x8. I should also mention that I have 3.42 gears, which is why I'm leaning toward the not-quite-biggest 31.5" tires.

As far as my off-roading, for now it's mainly the beach, but I would love to take my boys out to the western part of NC for some mountain adventures on the trails of the Pisgah National Forest. I don't see myself rock crawling any time soon, but you never know. For now, the only rocks near me are under 20' of sandy soil.

The Denali running boards are getting tossed. I've been on the horn with a salvage yard in PA who will be sending me some SLT rocker panels which will allow me to get some sliders some day (if I ever get the ambition to fabricate my own or come across something American made) and hopefully give more clearance than the huge wing-like Denali running boards. Being a garage-kept Southern truck, they're in great shape. Anybody know somebody who wants em? My Yukon's running boards are still in my attic, serving as a half-ass Christmas decoration shelf between the trusses. Been there since 2005.

I'll probably get the tires on Monday. Thanks for your time.

Chris

[v7guy]

I'd lean towards the 32s personally, the bigger sidewall you have, the more the tire will spread out when you air down and it should help you on the sand more (in theory). Practically speaking you're talking about a 1/4" difference in height, so it probably doesn't really matter. But 32s are fine with the suspension lift. I had to trim just a smidge (a small triangle) on the inside of my front bumper so they wouldn't hit while turning. I have a picture in my build thread.

You also may want to consider how common the size your looking at is. Is there a lot of tires in that size? It could be a big deal if you're away from home and need one.

It would probably be a good idea to toss on a trans cooler with the 3.42s and a bigger tire. I ran without one for a couple years with no problems, but it likely wasn't the best idea in the world.

[Marineguy]

Thanks for the input, Jason. I'm between the 255/70 and 265/65, and I think commonality is the deciding factor. Good point on finding an in-stock replacement away from home. I know a lot of silverados come with the 265/65s, but I don't know what, if anything, uses the 255/70 as OE. Sounds like kind of an odd size. Guess I'll go with the 265/65.
I think I'd rather just upgrade to some 4:10s over installing a trans cooler. I put up with 31s and 3.07s for two years in a wrangler way back when, never using OD until I finally put some taller gears in--and the whole world changed.
In my Yukon, installing a trans temp gauge was as easy as soldering a stepper motor to the board and sticking a needle on the new cluster face. I'm guessing there's no such easy fix for the voys.
Nice build!

[v7guy]

Thanks,

It's pretty simple to do a trans cooler, you can just tap into a couple lines along the passenger frame rail. Plenty write ups around here using a cheap trans cooler kit. Don't let that dissuade you from going to steeper gearing though, as you noticed in the past, it makes a pretty big difference.

[Marineguy]

Ended up going with the 265/65r18 destination ATs. They look great. When he pulled it out of the stall and turned the wheel it sounded like an M240G going off as the tread firmly rubbed the screw in the corner of the rocker trim. I had to trim a sliver off the front bumper, easy. In the rear side of the front wheelwells we had to unscrew the rocker trim, then bend the steel tab back another half inch, and drill and insert a new bolt to hold the rocker trim and fender lining together. Now it's all good. Removing the rocker trim probably would have solved the problem, but this mainly my 5'5" wife's vehicle, and with the lift the running boards actually serve a purpose, for now. Best question of the night:
She: "So... Why does my Envoy look all jacked-up, like something out of Jurassic Park?"
Me: "I don't know what you mean, babe. The new tires are a little more aggressive, maybe a little taller..."
I still need to add an OE coil insulator (which wasn't mentioned or included in my Arnott bags-to-coils conversion kit) to level the ass end with the front, but as soon as I get that in I'll post a build thread.
Overall, pretty satisfied with the whole expenditure. Got the tires installed by Firestone Auto on Camp Lejeune for $850, which was a lot cheaper than the tire sharks out in Jacksonville, with their E-Z financing.

[djthumper]

Where is a pic of it now?

[Marineguy]

Where is a pic of it now?

Well, it's not done to my liking yet. I need to toss a set of isolaters (or insulators if you're the gm parts guy) on top of the coils which I should have included when converting from airbags to coils, and I may do one more thing to get the tail level with the front. Right now it's exactly an inch lower, and I absolutely hate that look. I may be buying a set of Z71 springs tonight.
When it's done to my satisfaction I promise I'll document the build, but for now you can see in the lounge garage thread, in my garage, at night:
viewtopic.php?f=7&t=5695

[Marineguy]

Did I just break the double post rule by doing that? If so I apologize. I'd copy it from photobucket but my Mac is being screwy and really needs to be restarted. I think next time I'll show up in Firefox.

[kcb58h]

With a 2" R/C level kit, stock springs & struts, I am running 2656518 (31.6") BFG T/As on American Racing Trench 18x9 6x5 stock offset rims. Had to cut 8" front fender well. NO OTHER MODS.

[Marineguy]

With a 2" R/C level kit, stock springs & struts, I am running 2656518 (31.6") BFG T/As on American Racing Trench 18x9 6x5 stock offset rims. Had to cut 8" front fender well. NO OTHER MODS.

No spacers? Mine hit the control arms without the spacers.

[kcb58h]

I'm not sure why I don't need spacers. 18" dia. wheel maybe? Offset? I was told when I bought wheels & tires @ Disc. that they were just one of a couple of wheelsets that fit the TB w/o mods. Also, I think Disc. doesn't do spacers, right? I wouldn't b.s. anyone, this is my true setup. I've tried to post pics but can't make it work - see GMTN. I did misname wheels - they're called "Marin", not "Trench".

[ErikSS]

Since you don't have stock wheels, it's pretty likely you also don't have stock offset. It is nice to get that large of a tire without spacers though! Well done!