Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Ford Explorer Community - Maintenance - Modifications - Performance Upgrades - Problem Solving - Off-Road - Street
Explorer Forum Covers the Explorer ST, Explorer Sport, Explorer Sport Trac, Lincoln Aviator, Mercury Mountaineer, Mazda Navajo, Ford Ranger, Mazda Pickups, and the Ford Aerostar
Looking to put a 3 inch bl and 2 inch suspension lift with 33's stock gears 4.0sohc, getting about 13 in town 19 highway.. I have a lead foot. How bad will the mpg be roughly??
It depends on what gears you have. Look on the sticker on the drivers door, it should give you an axle code, then use this chart to figure out what you have. Then people will be able to give you some better info.
43 Open 3200 3.08
41 Open 3200 3.27
42 Open 4.10
46 Open 3.73
45 Open 3200 3.55
D4 Limited Slip 3200 3.73
D2 Limited Slip 4.10
L73 Limited Slip 3.73
actually with proper alignement, balance, and speedo recal, you should match or exceed your current numbers. It's like you just lowered your gears
I'll assume you have the stock 255/70r16's they are 30.05" in height
if you go to a 33" tire that is 9.091% larger which changes your 4.10 gears to 3.7269 (Edit: Corrected math mistake DUH) ratio. If your speedo is recalibrated to match you may see an increase in highway mileage. Although I would guess that the greater resistance of the wider tire will remove that advantage.
changing to 33's will make your truck act like it has 3.55 gears and 29" tires.my truck came with 3.55's stock and 4.10's with 33's make the speedo accurate to within 1 mph.i imagine somewhere around 4.56 or lower would bring you back to stock gearing.i lost about 3 mpg's lifting my ranger and using 33's.without regearing you might lose a little more but not too much.
J1211c has a '98 so the speedo is electronic (gets its signal from the rear ABS speed sensor)
rickcdewitt; said:
changing to 33's will make your truck act like it has 3.55 gears and 29" tires.my truck came with 3.55's stock and 4.10's with 33's make the speedo accurate to within 1 mph.
'98+ newer vehicles will have an incorrect speedo if tire size is changed (regardless of gearing changes) - i know b/c I regeared my mounty to 4.10s when I went to 32's and my speedo is off by almost 10%
Well I ened up getting 32x11.5's TT and Shackle lift. MY mpg is about the same i would have to say. MAybe even alittle better then stock it seems because the engine isnt working as hard. THanks for all the info guys.. ihave one more question tho.
If I get a 3 inch BL how roughly how badly will it effect the highway mpg going 75?
I am looking to do pretty much the same thing here but i have a 97 sport 5spd and my axle code is d4 i guess thats 3.73's limited slip (although i think the clutches must be gone cuz itl spin a tire of i get it in the air)
I am only looking for eventually 32's. You think i will need to get new gears? if so whats the best and cheapest option.. i would like to go with a no slip geared locker probably...
I am looking to do pretty much the same thing here but i have a 97 sport 5spd and my axle code is d4 i guess thats 3.73's limited slip (although i think the clutches must be gone cuz itl spin a tire of i get it in the air)
I am only looking for eventually 32's. You think i will need to get new gears? if so whats the best and cheapest option.. i would like to go with a no slip geared locker probably...
Your clutches are probably ok. A limited slip is not made to lock the wheel if it free spins in the air. You need to get a locker to do that. Depending what you want to do I wouldnt worry about gears. You may also want to think about changing the gear oil and don't forget to add the limited slip additive.
right now its a daily driver.. sometime soon i would like to also wheel occasionally.. mostly just point a-b but like i said i would like to wheel it....
Limited slip additive? i didnt know there was a special additive for them. Is it hard to change it?
question... does this mean i also have a limited slip in the front as well?
this info is base on my Grand cherokee ZJ, but I just recently switched tires from 31" all terrains, to 33" mud terrains, I didn't notice any major MPG drop, I have stock 3.73 gears aswell. as for the spedo gear, find a neighborhood speed radar box, drive by and see what the difference is. I drove by one; "your speed" 30- looked at the spedometer, it said 30 too. So the spedo was still dead acurate too. I guess I had good luck.
right now its a daily driver.. sometime soon i would like to also wheel occasionally.. mostly just point a-b but like i said i would like to wheel it....
Limited slip additive? i didnt know there was a special additive for them. Is it hard to change it?
question... does this mean i also have a limited slip in the front as well?
hard to change? nope, it's just a matter of removing the Diff cover and draining the fluid. Pull the fill plug on the axle (on the front driver side of the axle) Then add a bottle of the limited slip additive (very important) and your favorite full synthetic gear oil.
LS in the front? probably not, it was never an option, but you could always add something like an Aussie locker up front, but for street use I would just service your rear LS and call it a day.
thanks i really appreciate the info and help.. i am going to change my rear diff fluid this week.. cuz i don't know if it was ever done! 188000 hmm... anyways ill see if that helps out the rear l/s then if not i can look into a locker maybe.... thanks again!
and i am reallyitching to get my ex to the point i can runs 32's ... need $$$
what is the overall point/reason for an open rear end i have a 3.73 open and im pretty happy with it but i figured off road a l/s or pozzy would be better?
Wow this thread has really gone off topic
Everyone, in the future it is best practice if you start a new thread with your own question. It is the best way to get answers, as more people will see it.
what is the overall point/reason for an open rear end i have a 3.73 open and im pretty happy with it but i figured off road a l/s or pozzy would be better?
The point/reason for a open differential is that all diff's where open when they first started making cars, they are cheaper to build, and there are less moving parts. It's mostly about manufacturing costs. The downside is that only one wheel will actually be getting power.
A Limited Slip on the other hand is better for traction, more expensive, and is usually an option on most trucks. They are made to be a compromise between a locker and an open diff. They are smooth and will apply a certain amount of power to both wheels. However when one wheel is in the air more than likely your LS will not help much.
A locker on the other hand is not best suited for road use. When they unlock you will hear a distinct clunk from the rear end as the locker unlocks. There are smooth lockers that claim to be as smooth as a limited slip but give you the full power of a locker (such as the Aussie lockers)
as back to the mileage i have an 03 Ranger with the 4.0 with 33x10.50 yes 10.50 and i am making about 17-18 on the highway but in higher altitudes I was seeing mileage as good as 21-22. Be aware of your tire and wheel combo as it as hokie said will make a difference with my tires and alcoa rims (15X7) they are lighter than the original 16s i had on the truck to begin with
