Plus-One (+1) sizing... (1 Viewer)

[Makakio]

Okay guys - time is now to buy new shoes. Running OEM size now (which to me makes the truck look terminally under-tired), but I recently saw a stock GX on +1 (265x70x17) tires and it looked waaaay better. I have researched and understand this size fits w/o rub (or with only full-lock rub which can likely be remedied with the heat gun or dremel).

So the real question, which I cannot get data on: this is my wife's grocery getter and it's a gas guzzler - does anyone have experience with MPG drop going to this size? Corrected or uncorrected I don't care - I can figure that out if anyone has before/after numbers for city or highway or fairly even mixed driving. in 50/50 mixed we've been getting 17.5mpg for two years now.

Will be putting Michelins on it (LTX M/S2). 44lbs at this size (versus OEM 36lbs for the Bridge Duelers on it now) - a 19% heavier choice going to the Mich's - and of course they'll be larger in diameter - so I'm being realistic and expecting a drop - but how big?

Also, if you have any other insight into going +1 (handling, ride, etc) -I'm all appreciative ears. I'm doing it purely for looks, so if there are significant drawbacks I'd certainly like your thoughts...

Thanks!

 

[2002tii]

I've not really noticed a difference in fuel economy with my 255/75-17 BFG MTs. One thing I will say I really like is that they are LTs and not Ps; the firmer sidewall makes the ride less floaty but far from too stiff. Obviously it's a lot louder with the MTs, but I'd imagine an AT or all-season LT tire would be perfect for a pavement pounder.

I get about 18 mpg mixed. 20 mpg highway. 15 mpg if I'm just in town.

 

[Makakio]

Thanks tii - much appreciated!

47 views and one reply?!

 

[Nothinghead]

Thanks tii - much appreciated!

47 views and one reply?!

Patience young one. Welcome to the 120 section on 'Mud which doesn't get a ton of action.

I don't have a great answer for you because I've made a few more changes, LT265/70R17 Goodyear Duratracs and I've noticed about 1.5 to 2 MPG loss. This is likely a combo of heavier tires, larger diameter and wider lugs in the tread.

If you just want to look taller, I'd suggest going with the 255/75R17s that can be had cheap as take offs from Wrangler Rubicons. You'd get a taller size but not as much weight increase or tread footprint. That won't hurt your MPG as much

 

[GXO]

I have 285/75/17s Duratracs and about 800 lbs of toys and armor and I get 13-15 mpg regardless of highway or city. Only data point I can give.

 

[470SNC]

yeah I dont think one size up will affect the MPG that much IMO

 

[fantic]

Makakio have you done anything yet? I'm getting ready to replace the tires on my wifes 06 before winter. Going from Duelers to the LTX. Same thought process about the 70 series. Like to know how it works out for you.

 

[little_joe]

I only have 2 full tanks with the 255/75R17 Dynapro ATM's, my corrected mpg is a loss of 1 mpg from the stock tire size. This is primarily freeway (albeit rush hour), maybe 1/3 city & surface streets. I manually log every tank, miles driven (odo and corrected), octane, price, etc.

 

[Makakio]

First: THANK YOU FOR REPLIES. I've been off on vacation, off on business travel and buried under the post-labor-day return to work push - my apologies for being late on response. Appreciate the inputs here and sounds like a reasonable expectation on mpg loss.

Nothinghead: thanks for the suggestion about going 255x75x17s - I am indeed looking to go taller as the truck just looks under-tired with the stock aspect. Though I hear the 265 +1 setup can rub at full lock does anyone know if this occurs with the narrower width? Little_Joe?

Fantic: not yet. The fronts are to the wear bars and the shoulders are a little more worn than the rest of the tread. The rears are about 1/16th from the wear bars and look fine all the way across. If I didn't do Tahoe in the winter I'd probably rotate and work on getting another 6-7k out of them, but snow will force the issue sometime in November.

I'm one of those guys that researches researches researches, makes a decision, cogitates on it, then gets okay enough to pull the trigger. But it's a process as I hate thousand-dollar+ disappointments. Drives my wife crazy most of the time and I know a lot of people in forums like this are much faster and comfortable with mods (as a hobby), but you guys are invaluable source of info to me. So again, thanks.

 

[Makakio]

Additional question: if going to the 70 from a 65 series (that's an inch O.D.), do I need to also replace the spare? Or can that 65 series tire work as a limited-service (read: limp-home) tire without tooling my front or rear mechanicals? It sounds like a 265x70x17 barely underneath (and of course I'll look for room beforehand), but thos eof you with mech experience please chime in. If it needs to be same O.D. I'll go find a $110 spare, not another M/S2 to live under the truck haha...

 

[little_joe]

I'll defer to someone else on the rubbing issue as I've only run stock size and the 255's. I kept my stock spare - with open diffs all around, there will not be a mechanical problem if I have to run it, and you will be fine too. (If a front blows, I'd swap from rear to front, and put the undersized spare on the rear.) I am looking for a spare same size as my other 4, but 1) the Jeep guys who got them on their new rigs think they're gold-plated and the same value as a new premium tire and 2), again, not worried about size difference, so no urgency.

 

[IanB]

I put 265/70/17 Duratracs on our GX470 within days of picking it up, so I can't comment on mpg changes, but I will say it's made the truck a LOT slower in acceleration. My odo is now out by 6% which I use as a correction factor when calculating mpg, I average 15.4 mpg corrected. I've also noticed it struggles to stay in OD when towing my double snowmobile trailer at speeds in excess of 105km/h. If I had to do it over again, considering this is now my wife's DD and will not see any wheeling, I'd have stuck with stock size tires. It does look great though!

 

[Makakio]

Thanks for the info, guys!