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MPG loss with new tires....a question???
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Author:  midnitewolf [ Fri Dec 08, 2006 2:51 am ]
Post subject:  MPG loss with new tires....a question???
Looks like I am getting my libby this weekend if the deal goes through allright however, the first thing I noticed on the Libby I am trying to buy is that it has regular street tires, I think in they are stock 225/75R16 size. They have to go.

Anyway, I am wondering just how much your gas mileage is affected by going from street tires to say General Grabbers or Destinations. Going to probably just go up to the 235/70R16s or maybe I might convince myself to just go for 245/70R16s since I will likely get a lift down the road and don't want the tires to look to small in the well.

The reason I am asking is because I have a job where I am going to be driving 50-100 miles a day in the city and want to get an idea of just how much economy I am going to lose by going with All Terrain tires.

Also how much MPG do you think the lift will cost me in terms of economy?

Anyway, thanks for the help.

B.
Author:  Cacher123 [ Fri Dec 08, 2006 3:03 am ]
Post subject: 
Lifted & oversize tires on a 50-100 mile a day commute?
Buy a beater to drive to & from. It'll cost you less! :wink:
Keep the KJ for the weekends! :lol:
Just kiddin. I may be wrong but from what I gather, you shouldn't suffer too much. City driving is gonna kill ure MPG anyway and since you'll be in city traffic, any increase in wind resistance from the lift or rolling resistance from the larger tires won't be a factor. Maybe 1-2 mpg per as a loss.
Author:  XR [ Fri Dec 08, 2006 7:05 am ]
Post subject: 
I get a consistent 17MPG in my '02 KJ.Lift,245/75-16,skids and a locker.
Author:  Jeepjeepster [ Fri Dec 08, 2006 8:47 am ]
Post subject: 
I would probably stay with the 235/70/16 for best gas. the Grabber is a very aggressive tire. I had those in a 255/70/16 size and sold and went down to a 245/70/16. You probably wouldnt notice a difference going to a 235/70/16 Grabber. They are just a touch loud though.. :wink:
Author:  SAR02KJ [ Fri Dec 08, 2006 9:53 am ]
Post subject: 
WOW... my lifted kj only gets 12-13 mpg and i have a cold air intake lol... but i do live in a hilly area.
Author:  Video Guy [ Fri Dec 08, 2006 11:00 am ]
Post subject: 
With 245/70R16 Grabber AT2's, I average 17 mpg in city/suburban driving in the flat Midwest. I've had only one highway trip since I put on A/T tires but didn't pay any attention to my mileage. (It was a weekend anniversary trip with my wife. I had better things to do. :wink: ) I'm guessing 19-20 mpg with cruise control set at 60 mph.

1.5" front/2" rear Daystar lift's effects on mileage have been negligible, about 10 miles less per tank of gas.

Oddly enough, adding the spacer lift seems to have reduced the tire noise inside the vehicle. That, or my alignment is shot. :?:

You should do yourself a favor and replace the factory tires. Granted, the current tires are wider than the 215mm Wrangler ST's that mine came with in 2003, but a better tread design will benefit you and give you safer vehicle. I recommend the Generals, but if a smoother, quieter ride is very important, I'd spend $100 more on a set of Bridgestone Dueller A/T Revo. If you plan to lift during the life span of your tires, I would stick with 245. A wider track will compensate for raising your center of gravity, and minimize any increased likelihood of rollover. My personal experience is that my Liberty felt most solid unlifted with 245s, but even with my small lift, it still feels less "tipsy" than stock.
Author:  ROB SCHEIB [ Fri Dec 08, 2006 1:56 pm ]
Post subject: 
Just my two bits, I run 245/7016 GRABBERS on my '05 (gas), I just got a little over 22mpg on a highway trip this weekend. By the way, I've had many jeeps, and run many tires, these are IMHO the best bang for the buck you can get. Quieter on the hiway than in town, great traction, good solid feel, low price.
Author:  DarbyWalters [ Fri Dec 08, 2006 2:32 pm ]
Post subject: 
Seems like until you lift it you could just wear out the stock rubber. After you lift it you could buy an extra set of nice steel wheels with 245/75/16 MTs for offroad. When the stock tires wear out...get some 245/70/16 street tires.

Will keep your mileage a bit better...will save wear and tear on your aggressive tires. Seems like you would save in the long run.
Author:  gone_jeepin [ Fri Dec 08, 2006 4:30 pm ]
Post subject: 
i hate to change topic, but i really would like to know how yall are getting 17-22mpg especially who ever said they did mostly suburban driving, i seem to only be getting 15-16mpg with mostly highway driving in my stock 03 limited with the shiny 17"rims.
Author:  eggwhite93 [ Fri Dec 08, 2006 4:44 pm ]
Post subject: 
I get 13.5-14 MPG in my 05 with lift and 245/75/16 MTRs before the lift and with the stock tires I was getting 16.5 or so. That is 100% city/suburban driving.
Author:  BJ'naKJ [ Fri Dec 08, 2006 6:06 pm ]
Post subject: 
I lost quite a lot in mileage when I went from stock to a lift and 245/75 GY mt/rs. I had limited mileage stock, about 2k miles, but was around 25mpg. Now with 4k miles on the tires and lift, I've yet to get better than 20 mpg from a tank.
This is with an '06 CRD.
I really feel the gearing change from the tires. I wonder how going to a 4.10 would affect mileage now?
Author:  Gordo [ Fri Dec 08, 2006 7:20 pm ]
Post subject: 
I average about 15.3MPG with my 03 Sport with a 2.5" lift and 245/75/16 MTRs. I do about 70/30 highway/city driving.
Author:  XR [ Fri Dec 08, 2006 9:56 pm ]
Post subject: 
I don't know why I get good mileage.Until I read this I thought my mileage was mediocre.I do get better mileage on other peoples stuff than they do when I drive it.I am not exactly a slow driver either.???????
Author:  jason thompson [ Fri Dec 08, 2006 10:44 pm ]
Post subject:  Re: MPG loss with new tires....a question???
midnitewolf wrote:
Looks like I am getting my libby this weekend if the deal goes through allright however, the first thing I noticed on the Libby I am trying to buy is that it has regular street tires, I think in they are stock 225/75R16 size. They have to go.

Anyway, I am wondering just how much your gas mileage is affected by going from street tires to say General Grabbers or Destinations. Going to probably just go up to the 235/70R16s or maybe I might convince myself to just go for 245/70R16s since I will likely get a lift down the road and don't want the tires to look to small in the well.

The reason I am asking is because I have a job where I am going to be driving 50-100 miles a day in the city and want to get an idea of just how much economy I am going to lose by going with All Terrain tires.

Also how much MPG do you think the lift will cost me in terms of economy?

Anyway, thanks for the help.

B.




going to the 235/70 will be going less OD and more width
if you go with the 225/75 wich is 29.5" OD but a little less wide maby like 7" at the tread you will notice no change in milage
The change in milage that you see comes fom several factor the major is the OD it changes you gear ratio ,sorta, in the long run
the other is the width or how much tire you have on the ground when you are rolling more tire on the ground and it is harder to roll
The last is tire weight that is the obvious one a heavier tire is harder to roll
Put the 3 togeather and that is a recipe for poor MPG

If I were you I would look real hard at OD and width and then ask my self in the real world how much differance is 1/2" going to make off road cause it can kill your MPG on the highway also look at the weight of the tire you do NOT need an E range tire on a KJ it is a waste of money and will weigh a lot more than the same tire in a C load range wich in the long run will be better for every situation you could put a KJ in
the weeker side wall with low PSI will flex out better and give better traction so you will still get the width off road with the C that you can not get with the E cause it will not get flat enough and still hold a bead

need more info just ask
Author:  spoonplugger1 [ Sat Dec 09, 2006 9:19 am ]
Post subject: 
Seems the people who go to the Generals or BFG ATs lose at least 1 mpg instantly, we have 7 Libs at work and we talk alot about them. The people that went to a tire with a pattern like the Revo, don't seem to have enough change to notice. I'm running 245/70 Nokians with much the same pattern and I haven't noticed a mpg or power loss, but I also have a CRD which may make a difference.
Author:  Video Guy [ Sat Dec 09, 2006 1:26 pm ]
Post subject: 
gone_jeepin wrote:
i really would like to know how yall are getting 17-22mpg especially who ever said they did mostly suburban driving, i seem to only be getting 15-16mpg with mostly highway driving in my stock 03 limited with the shiny 17"rims.

I drive like my grandma, that's how. :D On the highway, I set cruise control at 60 mph. Rarely over, unless I'm really in a hurry to get somewhere. Goverment tests show something like a 15% drop in fuel economy for every 5 mph over 55 or 60. That adds up. The KJ's not a sports car, so I don't drive it like one.
Author:  habitTrail [ Sat Dec 09, 2006 1:30 pm ]
Post subject: 
XR wrote:
I get a consistent 17MPG in my '02 KJ.Lift,245/75-16,skids and a locker.

That there is one lucky guy. The exception, not usual results, unless maybe "all" your miles are highway miles. Which means, you went from about 21 on the highway down to 17.

Most of my miles are what you would call city. I went from 17 city to about 15 with lift, skids, bars and basket on 245/70's.
Author:  midnitewolf [ Sat Dec 09, 2006 9:24 pm ]
Post subject: 
Well I think the reason people notice the lose in mileage with the Generals is that they are very heavy tires from what I have researched. 38 lbs a each compared to the Destination which are 33 lbs each. That is the weight for the 235/70R16 anyway. Anyway that is one possible explaination. I will probably put on Destination A/Ts since they are lighter and only about $10 more than the Grabbers. Not as agressive a look as the Grabbers, at least from the pictures I saw but not bad either.

B.
Author:  2372ighost [ Sun Dec 10, 2006 10:00 am ]
Post subject: 
Last two tanks of gas in town city driving. 245/75R16 MT/R's 5sp manual 15.92mpg and 15.20mpg
Author:  jason thompson [ Sun Dec 10, 2006 10:10 am ]
Post subject: 
midnitewolf wrote:
Well I think the reason people notice the lose in mileage with the Generals is that they are very heavy tires from what I have researched. 38 lbs a each compared to the Destination which are 33 lbs each. That is the weight for the 235/70R16 anyway. Anyway that is one possible explaination. I will probably put on Destination A/Ts since they are lighter and only about $10 more than the Grabbers. Not as agressive a look as the Grabbers, at least from the pictures I saw but not bad either.

B.




5# and the same size tire will not make a difference
if you have any plans to wheel it I would go with the Generals if you are hung up on those 2
If ou dont need to have one of those 2 then I would check with a local tire shop ,one of the smaler "mom and pop" places, they can usualy get some that will be just as good as any other tire but cost $20 ,or more, less
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