I'm pretty sure if the OP was complaining about crappy mileage while towing something, or while loaded to the nuts they would have said something. But whatever makes you feel better.
gears and mpg
- Thread starter LUISJG
- Start date
Cole
Expedition Leader
Many many many jeep owners have added thousands of pounds of accessories to their rigs and things that create wind resistance, effecting their fuel mileage, where the lower gear set would actually help them!
But, beating you up on those obvious details makes me feel better:coffeedrink: Just stick with your blanket statements and snide comments. No reason to have an open discussion in a COMMUNITY of like minded people!
Obviously the assumptions are all you need!I was just pointing out that the higher gears don't "always" make for better mpg. Its possible to move the rpm too low for a given demand (elevation, load, terrain, tire weight and/or size) and make the load on the motor greater, using more fuel because it's not running at an efficient rpm for the conditions.
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I have heavy 33x13.5" tires and heavy bumpers... and even towing my trailer my best tank is within 0.6 MPG from my best tank when I was stock.
My 07 JKU with 33s, 3.21s, a 6spd and a very heavy front bumper could 24/25 MPG on the highway - and did on several occasions. Just don't ask how it did in the hills or worse, mountains.
But, beating you up on those obvious details makes me feel better:coffeedrink: Just stick with your blanket statements and snide comments. No reason to have an open discussion in a COMMUNITY of like minded people!
I was just pointing out that the higher gears don't "always" make for better mpg. Its possible to move the rpm too low for a given demand (elevation, load, terrain, tire weight and/or size) and make the load on the motor greater, using more fuel because it's not running at an efficient rpm for the conditions.
First off, it wasn't a blanket statement. I clearly said "if you're not in the mountains" and "if it's a lighter tire". And the OP is in Texas where for the most part, it's fairly flat. 4.10s with an auto and stock 32s, and when cruising at 60/100 (not in the mountains, bla bla bla) it puts the RPMs too high to get decent mileage. Which is why it's not even the default option, and customers have to select it when ordering a JK. I'm not the only person saying this... There's many others that have found the stock setup to be too low.
I think you'd be surprised at exactly what the efficient RPM range is for the 3.6L - not that I'm claiming to know bc I don't have a clue. But I have a tiny hill on my way home from work every day (it's hard to even call it a hill - more a bump in the road), and when going up it, you can feel the engine start to work a tad. Yet if I drop it a gear (iirc RPMs go up from ~1700 to ~19/2100), my instant mileage (according to my scangaugeII) goes down, not up.
Also, I never said higher gears make for better MPG (always, or otherwise). In fact I never even said the OP would get better mileage going to larger tires. Although I've heard of it happening to a bunch of different people. While my mileage has gone down (which I expected), it's barely noticeable (in ideal conditions, less than 1MPG - and that with me towing my trailer). So had I done the tires first (vs bumper/winch), it wouldn't be inconceivable that my mileage could have improved. As I said... I've read a bunch of stories of guys going to 34/35s and their mileage actually getting better due to it dropping the RPMs.
And just a note. I clock almost every single tank I put in it on a fuel app (every tank while on the road). I have 44k on my JK in ~23 months of owning it. Of that, 25k came from 3 road trips - of which I have a bunch of different driving - everything from mountain passes to the plains. My last JK was under geared (3.21s, 6spd, 3.8, 33s, heavy front bumper/winch). This JK while stock was over geared (auto, 32s, 4.10). Now with my heavy 33s I'm at a happy medium - under geared while towing my trailer in the mountains (specifically the passes), and slightly over geared while on the plains. I'll still go to 35s and do at least 1 trip south before I even consider re-gearing.
Anyway, all that said... ones driving habits will reflect more on ones mileage than changing the tires/gears/etc.
JIMBO
Expedition Leader
:sombrero: cole thanx, you're right-
My JKUR after almost 6 years, weighs about 5700lbs on a normal trip and I'm running 5.38 gears/w 33.6" hankooks-
My avg mileage at 70 mph is 17.2 mpg and when I tow my trailer (14.9mpg)-
As I said earlier you can't make a blanket statement about gearing,(one size fits all) they're all different !
CIAO
:costumed-smiley-007:wings: JIMBO
Many many many jeep owners have added thousands of pounds of accessories to their rigs and things that create wind resistance, effecting their fuel mileage, where the lower gear set would actually help them!
But, beating you up on those obvious details makes me feel better:coffeedrink: Just stick with your blanket statements and snide comments. No reason to have an open discussion in a COMMUNITY of like minded people!
I was just pointing out that the higher gears don't "always" make for better mpg. Its possible to move the rpm too low for a given demand (elevation, load, terrain, tire weight and/or size) and make the load on the motor greater, using more fuel because it's not running at an efficient rpm for the conditions.
My JKUR after almost 6 years, weighs about 5700lbs on a normal trip and I'm running 5.38 gears/w 33.6" hankooks-
My avg mileage at 70 mph is 17.2 mpg and when I tow my trailer (14.9mpg)-
As I said earlier you can't make a blanket statement about gearing,(one size fits all) they're all different !
CIAO
:costumed-smiley-007:wings: JIMBO
expedition4x4
Explorer
More details are needed from the OP before you can really help but at this point we can keep making assumptions, how about standard or auto? Mods attached to jeep to date whether you are running steel wheels or aluminuminum wheels, so we can determine better sprung vs unsprung weight. It really is not a black and white question.
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Thanks for the replies,
My rubi 2014 automatic came with 4.10
For some reason I feel that needs bigger tires, I had a 2011 sport auto and think it had 3.73 with 34 inch tires and im getting same milage with the rubi with 32,s.
This is not my first jeep and not trying to get high mpg but I never paid attention to gears before
My rubi 2014 automatic came with 4.10
For some reason I feel that needs bigger tires, I had a 2011 sport auto and think it had 3.73 with 34 inch tires and im getting same milage with the rubi with 32,s.
This is not my first jeep and not trying to get high mpg but I never paid attention to gears before
Depending on the tires, it's possible it might help, as it will lower the RPMs - but it's far from a certainty.
Just looked through my mileage history again. My best tank stock was 20 MPG - happened once on a windy road where I wasn't doing 100. My typical highway tank was 18-18.6 MPG. My best tank after modding my JK (heavy 33s, heavy bumper and winch), 21 MPG (ftn - fsj - which isn't flat highway). The rest of that trip (before getting the trailer) was between 17.5 and 18.5 MPG.
Tire weight also plays a part in this too. I ran cooper ST Maxx 285s for the past two years for the spring summer and fall, but put on trail master M+S for the winter in 265 that are over 20 lbs lighter per tire, makes a HUGE difference to my fuel milage. I am putting on 285 goodyear territory tires that are actually 2 lbs lighter than my trail master M+S. I am hoping that with the lighter tires, I should regain some of my milage. And it has nothing to do with the price of gas etc, or buying something other than a JEEP. Its about how far I can travel in the backcountry.