Same mileage in Full Time 4WD?

Bill.Barg · **Posted:** Wed Nov 14, 2007 7:48 pm

I know this is should not be right, but it seems like I get the same mileage in Full Time 4WD as I do in 2WD.
(actually, I am loath to say that MPG seems to improve. Can't be true)

Maybe this is because I do a lot of City driving (95%)???

Anyone else notice this?

DarbyWalters · **Posted:** Wed Nov 14, 2007 8:36 pm

Most of the internals are turning all the time in 2WD too...the weight of the 4WD hardware is also present...so mileage will not change much or any easily measureable amount most likely.

Albert · **Posted:** Wed Nov 14, 2007 9:27 pm

Mine is not a CRD so pardon me for interupting your post but I thought the title was interesting.

With my 3.7L I do not seem to notice a measureable difference between full time and 2hi.

As you were.....hehe

Reflex · **Joined:** Mon Jan 29, 2007 8:48 pm **Posts:** 567

In highway driving I seem to lose 1-2mpg staying in Full Time 4WD, however for around town I've never noticed a difference.

Ripple · **Posted:** Wed Nov 14, 2007 9:58 pm

over about 20 tanks I found that I lost about .5MPG when in full-time 4x4 all the time.

since then I have found that really its a no brainer with on-the-fly engament of the 4x4, if it starts to rain, pull the lever, when it drys up, push it down. no real reason to leave it on or off all the time, we did pay for it afterall, may as well use it.

boilermaker2 · **Posted:** Wed Nov 14, 2007 11:11 pm

The only time I drove for an entire tank worth of fuel through it in 4wd I got 19 instead of the customary 22. 19 in snow pack and no problem? Just shy of 400 miles in a vehicle in 4wd? 19 mpg might have been because of snow-fun-itous. Who knew! :shock:

Boiler

coldkj · **Posted:** Thu Nov 15, 2007 1:26 am

During the two winters I've driven in 4wd here in Southcentral Alaska my mileage has been, around town, 16mpg. In the summer, it's consistently 19mpg. Strictly town, and in the winter the fuel changes. But there's no doubt in my mind that mileage decreases when I'm in full time 4wd. Maybe it's the fuel, maybe I'm driving slower in the winter, but this is clear observation.

boilermaker2 · **Posted:** Thu Nov 15, 2007 9:58 am

I would think that in Anchorage you might have a couple of things going. First of all, if it is all-town driving, I would almost bet that the drag of your alternator never turns off. I would be curious as to how long your battery lasts. With the glow plugs staying on (they do under cold conditions until engine warms), the additional "static" heater (or whatever), your rear defroster, headlights (dark) and all of the other little heaters and widgets the thing has I would think that the jeep's alternator is screaming for 9 months out of the year. I don't think it is a 3 mpg drop drag but I bet it is good for a couple. I better your little engine never heats up either which would be good for another mpg or two. However, the ability to drive in Alaska is very cool. I'm jealous.
Scott

coldkj · **Posted:** Thu Nov 15, 2007 10:53 am

Scott, I think you're right about the engine temp. I have a radiator blocker I use starting when the ambient temp falls below 40F, which is typically in October, and I use it until April. The daylight thing has most people confused. We have about the same number of hours of daylight as the rest of the country, per year. It's just that we get it at different times of the year. But the fall and spring equinox occurs here on the same days that it does in Indiana, in March and October. In any event, the winter fuel, the cabin heater, the short distances I drive, the ARB bumber and the lower tire pressures I run in the winter all conspire to rob me of fuel mileage. And when I use 4wd full time, it drops another mile or two. BTW, I'm hoping that the SEGR ORM will fix a little of that, and I bought a new muffler yesterday (Aero 2525). An ECU flash is planned for next week. And it is nice to be here in AK.

Same mileage in Full Time 4WD?

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