Concequences of larger tires with stock gearing?

tjkj2002 · **Posted:** Fri Aug 13, 2010 8:56 pm

Unplug 2 coils and that is what you will feel like and your mpg's will dive as you will be on the gas more to get to speed and maintain speed.

When I went from 3.73's to 4.10's with my 265/75's I gained 6 mpg's,I had the same tires,same rims,and lived in the same area and even added more weight and gained mpg's and power.

JL Rockies · **Posted:** Fri Aug 13, 2010 11:43 pm

your trans will downshift a lot trying to maintain speed too... and that can't be good.

JeepinJarhead03 · **Posted:** Sat Aug 14, 2010 1:29 am

id borrow toms tires for an afternoon and see what you think someone around IL / OH has to have a set you and ride for a day

i didnt think there was a big difference in my 245/75 e's and my 255/70 p's until i wore out the E's and put the 255's back on now i want something in the middle but at 30" height

i just need better quality tires is all lol

InCommando · **Posted:** Sat Aug 14, 2010 2:24 am

JJH, you should try 265/70's.... might work for Yello, too....

InCommando · **Posted:** Sun Aug 15, 2010 6:12 am

I ran a set briefly, but did not take pics....

They are virtually the same height as a 245/75 but fill the wheelwell better due to the extra width. The width is the same as the 265/75's. I had no rubbing issues with stock rims. They make a visible difference.

KJ 119 · **Posted:** Sun Aug 15, 2010 10:01 am

There's got to be a pic of Tom's 265/70 BFG AT's here somewhere.Perty sure that was his old tire size.

2006 KJ · **Posted:** Sun Aug 15, 2010 2:10 pm

with 3.73's and an auto 4.10's would be nice on the tranny and skinny foot flopper with 265/75's. alum wheels and tire weight would help a lot compared to steel wheels and mud tires.

tommudd · **Posted:** Tue Aug 17, 2010 4:47 am

265-75s and 3.73s have me running with the OD off most of the time just for power and speed. Once I get to rolling at 75/80 its not bad, anything under that. If you think you want that size I would consider doing the 4.10s, I have been waiting and waiting for a guy to do mine since last fall, can't wait to have something to drive normal again.
Coming back from the bad lands I ran with the OD off all the way home at 55/60 just to say...
265-70s are OK and no problems, ran them for a while and they were great! HUGE, read HUGE difference between them and the 265-75s!

SweepnChoke · **Posted:** Tue Aug 17, 2010 7:01 am

yellocoyote wrote:

With the recent "boost" in my lift, my 245/75's are looking a little on the small side.

yellocoyote wrote:

I am willing to sacrifice a little tire width to improve tire diameter... but by no means want to run 'skinny' tires either.

265/70 isn't going to look any different then the 245/75 she's already running, saying as how she is looking to increase tire diameter, and is willing to give up some width if necessary.

245/75/R16 approx 30.5" diameter, 8" width
265/70/R16 approx 30.7" diameter, 9.7" width
265/75/R16 approx 31.7" diameter, 8.5" width

My suggestion would be 235/85/R16 31.7" diameter, 7.1" width, you get the increased diameter of the 265/75 with out the additional weight. I just picked up a set of Rubicon rims with 265/75/R16 goodyear mtr's that were already mounted on them. I've only driven it like this for a few weeks with a manual trans. I am removing the 265's, and putting my 245's back on, too much power loss for me though the 245's definately look a little tiny with the lift. My preference is to regear, then put 265's back on, but I am still toying with the idea of 235/85's with out regearing, or at least until I can afford to regear. I know the 235/85's are fine on a 7" stock rim, but I'm not sure how they will fare on the 8" Rubicons.

KJ04 · **Posted:** Tue Aug 17, 2010 7:24 am

yellocoyote wrote:

I was having a conversation with the hubby the other day, and I'd like some other points of view before making a decision.

I'm toying with the idea of putting 265/75's on my KJ next year sometime as my BFG AT K/O's are going to be pretty well worn by then. With the recent "boost" in my lift, my 245/75's are looking a little on the small side.

In my understanding, if you go to a larger tire (say something like a Treadwright 265/75, E rated tire) it's common practice to regear to 4.10's. He seems to think that I wouldn't need to do this because I'm not an overly-aggressive driver - on road or off (I tend to be pretty easy on the accelerator when wheeling). Is he correct in his assumption?

I understand that the larger tires are more taxing on the differentials... so, if I opt not to regear, what kinds of things could I expect to happen?

If power loss, constant downshifting out of overdrive on small grades, and a very noticeable drop in gas mileage is not a problem for you, by all means go with the 265/75/16's. Otherwise, stay with the 245/75/16 or the 265/70/16. :wink:

tjkj2002 · **Posted:** Tue Aug 17, 2010 10:14 am

SweepnChoke wrote:

yellocoyote wrote:

With the recent "boost" in my lift, my 245/75's are looking a little on the small side.

yellocoyote wrote:

I am willing to sacrifice a little tire width to improve tire diameter... but by no means want to run 'skinny' tires either.

265/70 isn't going to look any different then the 245/75 she's already running, saying as how she is looking to increase tire diameter, and is willing to give up some width if necessary.

245/75/R16 approx 30.5" diameter, section width 9.8"
265/70/R16 approx 30.7" diameter, section width 10.5"
265/75/R16 approx 31.7" diameter, section width 10.5"

My suggestion would be 235/85/R16 31.7" diameter, 7.1" width, you get the increased diameter of the 265/75 with out the additional weight. I just picked up a set of Rubicon rims with 265/75/R16 goodyear mtr's that were already mounted on them. I've only driven it like this for a few weeks with a manual trans. I am removing the 265's, and putting my 245's back on, too much power loss for me though the 245's definately look a little tiny with the lift. My preference is to regear, then put 265's back on, but I am still toying with the idea of 235/85's with out regearing, or at least until I can afford to regear. I know the 235/85's are fine on a 7" stock rim, but I'm not sure how they will fare on the 8" Rubicons.

Fixed some #'s for you.The tread width and section width for a 265/70 and a 265/75 are the same as both are 265mm wide.

Oh and the tire installer is going to really hate you for trying to mount a 235 on a 8" rim and they will end up drastically shorter then a 245/75 if they get it mounted on a 8" rim.You also will ruin the tires very fast on a to wide of a rim.

SweepnChoke · **Posted:** Tue Aug 17, 2010 11:21 am

tjkj2002 wrote:

Oh and the tire installer is going to really hate you for trying to mount a 235 on a 8" rim and they will end up drastically shorter then a 245/75 if they get it mounted on a 8" rim.You also will ruin the tires very fast on a to wide of a rim.

Thanks for the info TJKJ. I was pretty sure I'd be doo doo out of luck mounting a 235/85 on the 8" rim but wasn't positive, now I know it isn't even worth trying.

So looks like I'll be running 245/75's until I can $re-gear$.

Here is a pic of a Liberty with 235/85 on stock rims, not sure if he is a member of this site or not

icarl's liberty

http://www.cardomain.com/ride/3250037

STINGN · **Posted:** Tue Aug 17, 2010 1:23 pm

My next tsize is 235/85

JL Rockies · **Posted:** Tue Aug 17, 2010 7:28 pm

If God owned a KJ it would have 235/85R16 tires installed. You don't need pics of my rig because you've seen one of the 7 Wonders of the Wheeling World in person.

DirtyKK · **Posted:** Tue Aug 17, 2010 7:50 pm

IMO the 235/85 look awkward on a Liberty. So does a 245/75 on anything over 2" lift. I would go with a 265/70 which is pretty much a 31x10.5. Also look at tire weight as well when purchasing cause it also makes a huge difference in power and mpgs. I used to run 265/70 ATs on 16x8 soft 8s and now have 265/75 on Moabs. I can tell they're lighter while pulling off but also notice highway speed takes a little more to keep up. I haven't been able to check mpg's cause I just got em on but I'm hoping to stay around the same for now. Looking forward to regearing in the next month or two.

evil libby · **Joined:** Thu Nov 13, 2008 11:41 am **Posts:** 296

if you look under my post for flat fenders you will see the 265/75/16 treadwright and Love the e rates as well never had to change my gear set or no ploblems with the tranny an stumpjumper my wheeling buddy will say the same no need to change them you might give a lil in the mile you lose per gal but save some mony in the long run gear set are to much for the 30a and brack to easy with the e rates on I now this I am missing my 30a as of much

riptricket · **Posted:** Mon Aug 23, 2010 3:23 am

http://www.quadratec.com/jeep_knowledgebase/article-15.htm

InCommando · **Posted:** Mon Aug 23, 2010 10:11 am

There is a definite visual difference between a 245 & a 265, no matter the aspect ratio. I wonder if the person who posted otherwise has ever even seen them?

SweepnChoke · **Posted:** Mon Aug 23, 2010 11:49 am

InCommando wrote:

There is a definite visual difference between a 245 & a 265, no matter the aspect ratio. I wonder if the person who posted otherwise has ever even seen them?

Yes, but she is looking to increase tire diameter, not width. Going from a 245/75 to a 265/70 isn't going to increase her tire diameter much, width yes.

Concequences of larger tires with stock gearing?

Who is online