Gas mileage and auto-locking hubs

Has anyone heard that if you change out your auto-locking hubs for manual locking ones it gets you about 5 or 6 more miles to the gallon?

Total bs.

Pull your front driveshaft and see if it improves.

Pulling the driveshaft won't do anything. I already tried that with no noticable gain in fuel economy . . .

that's what I was saying. Pulling the front ds will essentially do the same thing as manual hubs.

You won't get any gain. But if you want to try it, that's the way to do it.

Wouldn’t manual hubs prevent you from spinning your front axels? I have no idea about any mileage improvements, that’s why I asked you guys. Some old guy told me that.

I can understnad all of the questions about fuel economy as of late, but really.....

(begin general rant)

If you want economy from a daily driver, buy something that gets good mileage (30 mpg+ is good in my book). If you want one that goes the places an XJ can take you AND get good mileage, you are not being realistic.

If funds are tight, get an older economy car and park the XJ for a while. I have a Dodge 2500 for towing, not commuting. When I drive it I don't moan about 16 mpg empty, 10 loaded. I drive an XJ for recreation, I only monitor mileage as an indication of overall running condition. I commute in a '93 escort wagon that I have no more than $1200 in and I get 32 mpg out of. I don't complain that it's a gutless wonder on hills and on ramps. Each vehicle has a purpose and is built to satisfy that purpose first. Anything beyond that will be a compromise. The sooner folks understand that and stop trying to get 30 mpg form an SUV the better off we'll all be.

(end general rant)

There isn't much you can do other than to maintain the vehicle in a good state of tune and drive gently to increase overall fuel efficiency of the XJ. Sorry.

non-stick said:

I can understnad all of the questions about fuel economy as of late, but really.....

I commute in a '93 escort wagon that I have no more than $1200 in and I get 32 mpg out of. I don't complain that it's a gutless wonder on hills and on ramps. Each vehicle has a purpose and is built to satisfy that purpose first. Anything beyond that will be a compromise. The sooner folks understand that and stop trying to get 30 mpg form an SUV the better off we'll all be.

Click to expand...

We must be brothers-from-another-mother.....

My MJ is a recreational vehicle, and gets at best 20 MPG, downhill with a tailwind, on banana peels.
My DD (right up until last Saturday when I blew something up :explosion in the #4 cylinder :crying: is a 94 Escort with almost 170K miles on it. Damn thing gets (or got) close to 40 MPG in mixed driving....

I will say that the MJ gets slightly less mileage than it used to, since I have the CAD shimmed over to bypass the vaccuum crap on the D30. If I had to guess, I'd say maybe about 1 MPG less economical.

Jeff

OKinNC said:

Has anyone heard that if you change out your auto-locking hubs for manual locking ones it gets you about 5 or 6 more miles to the gallon?

Click to expand...

Two points about this question:

1) Autolocking hubs only lock when you engage 4WD. For normal highway use in 2WD they are unlocked. That's why they are called "autolocking" hubs. There is no advantage in fuel economy because they are unlocked -- just like manual hubs.

2) The question is irrelevent here, because the XJ never came with autlocking hubs.

No because if you bought manual hubs, only the wheels will spin.

With XJ hubs, the drivetrain spins to the T-case.

non-stick said:

I can understnad all of the questions about fuel economy as of late, but really.....

If you want economy from a daily driver, buy something that gets good mileage (30 mpg+ is good in my book). If you want one that goes the places an XJ can take you AND get good mileage, you are not being realistic.
The sooner folks understand that and stop trying to get 30 mpg form an SUV the better off we'll all be.

There isn't much you can do other than to maintain the vehicle in a good state of tune and drive gently to increase overall fuel efficiency of the XJ. Sorry.

Click to expand...

So let me see if I understand, you mean to tell me that not even acetone will get me 60 mpg out of my XJ?


Doh

that's because there are NO hubs on an XJ. Auto locking hubs would disengage the wheels, like on a ford. Manual hubs and auto locking hubs do the same thing, except auto locking hubs lock ...wait for it...automatically.

The closest things to locking hubs the XJ/MJ ever had was the axle disconnect system in the early years. Jeff had a disconnect axle in his MJ, then he shimmed it over to be a full time connected axle. He notice a "slight" decrease in mileage. If you spent the $1K to put locking hubs in your XJ you would see a "slight" increase in fuel milage. You can buy a whole lotta gas for $1K.

raypla said:

So let me see if I understand, you mean to tell me that not even acetone will get me 60 mpg out of my XJ?


Doh

Click to expand...

Well you might if you also:

removed the front driveshaft,
installed a"Tornado" in your air tube after
the K&N air filter cold air intake kit,
added headers,
reamed out the cat.,
ran 3" exhaust pipe all the way out the back, and
installed a ground effects package to improve aerodynamics.




Oh, don't forget the 3lb coffe can muffler that sounds like an angry hornets nest.....

I asked the same question earlier today in a different thread. Best responce I received was from non-stick: "Considering you're driving the aerodynamic equivalent of a brick, suddenly the extra little drag the front driveshaft may induce isn't that big a deal. ....." LMAO when I read it.

But this kinda sums it up for me. My XJ is a BRICK. It's even brick red

That's why I drive a beat up 1990 toyota corolla that gets 30mpg to work every day. Bought the toy 6 years ago for $750 and have maybe $1000 more into it. 200k on the clock and still hummin.... and ya can't beat the mileage with a stick !

Motrout
+++ It's a Cherokee thing.... Chrysler doesn't understand ! +++