realistic MPG and comfort thread..

[rotozuk]

Ok, seemed to be some interest on this topic on the photo thread.. Thought it might deserve its own thread.

The discussion was what options are there for a potential expedition rig that is comfortable, has long range, can carry gear, semi-capable offorad yet still returns better then 20 mpg.

Some people suggested Toyota mini truck with a 22R. My experience is that it is not comfortable (cabin is small) and does not get 20 mpg when carrying a load.

Samurai - Comfortable??? Are you kidding? Yes, they actually have more room then a Toyota Mini truck, but that is not saying much. The overall comfort sucks.

I'm surprised to hear a diesel Liberty gets better then 30 MPG. That is pretty darn great if it is true. And being diesel, it is prime for a veggie conversion. :D

I toy with the idea of getting something like an FJ60 or similar and dropping a 7.3 Powerstroke motor into it. You can get the motors pretty cheap and would return pretty good fuel numbers on such a light vehicle. (Light compared to the Ford!)

Here in the US our diesel choices are very limited. We have the trucks, the VWs and some old Mercedes... Very little else. Very little. I wish we had more options for say a 3 liter turbo diesel.

-Wayne

[Mieser]

The owner of AEV built a long wheelbase TJ with the Liberty power train ( 2.8 CRD, 545 auto, and np242 ). He is getting right right about 20mpg pushing 37s on the interstate at 75mph.

The downside is that he will NOT do the swap again. There are some round about ways that the swap might be able to be done at home, but getting everything to work like stock is damn near impossible for the DIY type person. the biggest problem if the interface between the TJ PCI network and the KJ CRD can-c network. The factory KJ application of the diesel has a front control module to provide some translation functions but you would still need to make other things work for the TJ. There is a great thread I started about this over on the AEV forum.

Mopar performance is toying with the idea of providing a 2.8L CRD diesel conversion using the military version of the TJ as an engine donor. That engine is far less complicated without the EGR and coolant heater.

The golden question is how much are you willing to pay for a 3 liter diesel engine for re-powering vehicles in the USA? I have been trying to organize something for a few years now...it is proving difficult.

[RockMolester]

My buddy's stock Liberty CRD gets about 22mpg in town and 29 on the highway.

[grocery getter]

I looked into a diesel liberty buy what turned me off were the transmission problems.
http://www.google.com/search?hl=en&q=jeep+liberty+transmission+problem&btnG=Search
There was also someone on this board that bought one and ended up having to have the dealer buy it back.
http://www.pirate4x4.com/forum/showthread.php?t=555671&highlight=jeep+liberty
The motor seems to be the best part of the truck and there are rumors of them being offered as a crate motor.

[bowtied_micky]

The only reason I would shy away from a 7.3 is that its a very heavy beast. I would bet that the frame would need boxed, the suspension would need serious mods and the size of the engine would stuff the engine compartment. I am a fan of the qirky 6.5l diesel. They are fairly cheap, if you know a few simple mods they are very reliable with good power and give good fuel mileage. They bolt up to standard chevy mounts, use a standard chevy trans. just a thought


micky

[DAMRON QUEENER]

What kind of milage do you think a fj55 with a 6.5 would get?

[HahnsB2]

PSDs should only be removed from vehicles, never swapped into one... Cummins 4BT is where it's at, typically 25-35 MPG depending on how large of rig it's put in, fully mechanical so no electronic shit to deal with either.

[Kiwipushrod]

Hey Guys,

I like the idea of this thread, because I'm trying to build just that.

The problem with diesel is You cant see any more bang for the btu's, if it's a dollar more per gallon. Not mentioning more accquisition, maintenance cost, and weight.

Am I missing something?

Thanks, Kiwi

[halbritt]

The real MPG kings in serious offroad vehicles that I've seen are Cummins 4BT swaps into half-ton chassis. I've seen a few half-ton rigs with the 4BT swapped in that claim ~25MPG. If one can find a P7100 4BT, it will take all the same fuel-injection performance bits that go into the 2nd Gen Dodge Cummins 6BT.

My rig is a '96 Dodge Ram 2500 with the 6BT. I get around 18MPG mixed. The truck is on 35s and has no mods for fuel economy other than a camper shell, which may help some. A new set of injectors and pump timing should yield a few mpg improvement that might get me north of 20MPG. It's not really uncommon for folks to claim ~22MPG on a stock truck.

[85blue4runner]

Cummins 4bt if you have the height or can make it, its about 750 pounds dry without accessories so not light.

An alternative would be an OM603 or 606 Mercedes, some like the OM617, I dont. An expo rig is usally heavy for its size, so 20mpg on the highway may be a stretch. You will never see that off road. Hwy mileage of 14-17 may be more realistic, but I could be wrong.

A 3/4 ton diesel can easily get 20MPG with some mods dep on your make and model, it may even get that stock. Just not sure how great of an expedition platform it would make dep on your terrain, location, etc. Not a bad choice though if you get one without all the electronic crap on it...

Only one way to find out...

[gabroxy]

Here is an MJ (Commanche) CRD swap in the works
Naxja (http://www.naxja.org/forum/showthread.php?t=955062)

[GRMhick]

If your looking at a diesel swap on a 60, Id be looking at the isuzu motor. The box trucks are easy to find in decent shape for under 5k, and the motor is an easy swap to an old cruiser.

But, IMHO, I would rather have reliability, and good availability of parts than mpg. Its nice being able to go to the local parts place for a starter. For a good expedition rig, I'd much rather have an 80 or 100 series that gets 14 mpg, then something with odd ball parts (which take a week to ship it) so I can get 20. That one time you are 4 days late for work, because your truck was broken, will more than justify the added expense in fuel.

[DZLCJ7]

My CJ7 w/ a 4BT gets 30mpg with a bunch of junk in it. When it comes to comfort though...its as comfortable as any 25 year old leaf sprung vehicle can be. The nice part about the swap is that I have used all parts that you can get at a parts store, this includes driveshafts. I guess the only oddball part is the NV4500 to D300 adapter.

[czechsix]

Yah, I'll chime in on the 4BT also. It's a "six of one, half dozen of the other" thing though. I went through the same issues and eventually went with something that could handle more weight, tow more, and we can sleep in it. 15-16 mpg isn't too bad, wish I had more range though.

[Screwzer2]

What kind of milage do you think a fj55 with a 6.5 would get?
Considering my FJ55 with the stock 4.0 liter got about 9, I'd say you're lucky to get it to 7 MPG. An FJ55 ain't the smoothest when it comes to airstream.... more like a brick.

I figured I was doing pretty good with my 89 XJ with 4:56 gears and 33s getting 14 MPG.

[WILLD420]

Anything over 10 is pretty decent in a fullsize during off road excursions. My 6.9 Ford Diesel gets about 10 running hard all day in the snow or sand. It will pull 15 all day long at 75 mph. On flat level dirt roads keeping rpm's down low and speeds at 45 or less, it will pull 17-18 pretty easy.

My Ramcharger with a TBI 360 got 12-14 with the stock tires. On 35's with 3.55 gears it gets 8 and it's a total dog. Someday it may get a 4b, but right now it does everything except pass a gas station, and gears are on the way soon, so that might improve soon too.

[roscoFJ73]

Considering my FJ55 with the stock 4.0 liter got about 9, I'd say you're lucky to get it to 7 MPG. An FJ55 ain't the smoothest when it comes to airstream.... more like a brick.

.

Others who have 6.5 fitted to 60 and 70 series Toyota report a big improvemnet over the gasser. The 60 and 70 are not all that wind friendly either

[cbrogers]

What about the Dodge Sprinter / Mercedes box vans? It is supposed to be a 5 cyl. diesel and get great mileage for a box van.

I imagine that availability is tight, but is this what they use in the rest of the world too?


Carl

[mattygwheeler]

any bj landcruiser should do you, for comfort find a 60, 70 or 80

[JESSE_at_TLT]

Our extra-cab V6/5spd Tacoma with 33x10.5x15 BFG's pulls 18-20mpg. Off-road and loaded, it still never dips below 16-17mpg.

What kind of weight can a 4BT pull? I'm trying to decide whether to swap a 4BT or a 5.9L Cummins into a '72 Suburban.

[boom harvey]

What about a Dodge Power wagon with a cummins swap and the new 6 speed hand shaker? Your 456 gears will hurt fuel but could be re-geared for better fuel. You get factory lockers and a 12 warn alreadied buried in the nose. The Hemi will yeild about 10-12 mpg but the cummins should get you closer to the 20-22 mpg marker.

[JESSE_at_TLT]

Uh, why wouldn't you just put a winch and lockers in a CDT?

[boom harvey]

Uh, why wouldn't you just put a winch and lockers in a CDT?

The power wagon is not just lockers and winch, you pick up a factory rig that is designed to be an off -road and is beefier then the stock version. I am not sure of his budget and his skill level. I would not tackle a gas to diesel swap myself, but would have to think that if you went with a dodge truck and swapped in an optional engine for the stock version that you would run into less electrical gremlins and have an easier time finding your electrical components to prevent crazy dead time with electrical issues. Just offering a thought, and you can get it as luxury inside as you want

[JESSE_at_TLT]

The power wagon is not just lockers and winch, you pick up a factory rig that is designed to be an off -road and is beefier then the stock version.
Oh, fuck me.

[Elwenil]

I've said it before and I'll say it again, the Power Wagon is an overpriced joke. Start with a normal CTD Dodge, which already has axles as good or better, and heavier suspension than the Power Wagon and add a winch and normal sway bar disconnects and poof, you have a better truck without paying for the "Power Wagon" name that has no business on such a joke of a truck with too many gadgets.

[WILLD420]

I've got an 02 CTD 2500 shortbed 4door (Batwing Doors). Not too many places I care to try and go that I can't get too with only a powerlock rear, 5" lift and 35's. A front locker, and a sway bar disconnect would be nice, but there are places that you really don't want to try and get a 7K lb truck with most of the weight on the front tires. Mine gets crap for mileage, I get 15 empty, 10 or less pulling heavy. I have no idea why, but it's always gotten crap for mileage. I've put 20K miles on it and changed all kinds of things hunting better mpg, no luck. It runs good, but I'm not ever expecting more than 15 empty out of it...

[Berne]

Our extra-cab V6/5spd Tacoma with 33x10.5x15 BFG's pulls 18-20mpg. Off-road and loaded, it still never dips below 16-17mpg.

What kind of weight can a 4BT pull? I'm trying to decide whether to swap a 4BT or a 5.9L Cummins into a '72 Suburban.

Jesse,
I think, geared correctly, a 4bt would do just fine in a suburban....so long as all you wanted to do w/ it was just drive the suburban around. most 4bt's spend their whole lives pulling those bread vans around...which prolly weigh at least as much as that 'burb, and are litterally a box moving through the air....
but, at the same time, its going to be no hot rod. I'm guessing a 4bt turned up a little will be alot like an old stock 350....but should net much better milage.

I'm just getting into a new project here....its gonna be a 4bt powered 78/79 bronco....I'm thinking 4bt - zf 5spd....I'm hoping for mid-20's at a comfortable hiway cruise. It won't set the world on fire....but I've got other rigs for that. I just want 'adequate' power to get it around, and have a 1000 mile range w/ 50 gal's of fuel.

--B