I was looking at a popular science magazine and saw a article for the VW Twin charger 1.4 TSI that puts out 172 hp and 177lbs of torque with 45mpg highway in a VW Golf(i think its called a rabbit here in USA) so i thought that if you could put this in a CJ7 that weighs a little over 3000lbs similar to the Golf you could have a pretty strong engine and get great gas milage. While this engine might not be as strong as a 4.0 it should out preform the 2.5/2.4s(125-147 hp 150-165 lbs) in the TJs, it would have more hp than any stock CJ and even with no aero dynamics you should still get at least 30mpg? so this could possibly make a nice daily driver or something to cruise around the lake with.
but, i don't really know anything about engine swapping or transmissions so correct me if I'm wrong on any of this.
all i know that i got a 4.0 in my TJ and ZJ and i get 13 and 15mpg and don't do any real offroading so a drop in torque for 30+mpg sounds good to me.
Best option for good highway mpg in a Jeep would be a diesel. By nature, they're more efficient at part load, so you can have a crap-load of power AND good mpg. Some easily removable (for off-road use) aero mods would help on the highway as well.
There is post in the YJ forum about doing a conversion with a Mercedes engine. I had a Mercedes with that engine and I expressed my thoughts. I think it would be a waste of money. I was verbal beat down for it, I did over state my point and that may have been part of the reason.
For the $ and hassle just buy a second car that gets the mileage. If you like a challenge and aren't concerned about money and a time line go for it.
To date there is nothing posted about the project being completed so I am not sure if it was successful. Another person who was working on it seemed near completion but there were still issues.
My issue with that motor is turbo lag. Somebody mentioned doing a swap with a VW TDI motor. Those motor don't make their power until the RPMs are built up. Not sure how ideal that is for off- roading, I guess it depends on how you wheel.
I just don't see the point in laying out all that money to rebuild or rely on a 10-30 year old motor, and then spend all the time and money to try to make it work in another vehicle just to get better mileage. If better mileage is the goal there are other vehicles you maybe want to consider.
Depending on the state you live in you could also have problems registering it.
01 TJ, 34 Super Swaper 34x10.5 bias, Winch, locked, belly up, some armor.
search for 4bt conversion.... Cummins Turbo Diesel puts out over 350ft lbs and after tweaks etc. can easily obtain 30mpg. Few people have done it, and hell, if I had the proper working knowledge of diesels, I'd do it too.
[COLOR="DimGray"]SILVER JEEP CLUB MEMBER #46[/COLOR]
i was going along the lines of being cheap and not seeing much off road but these all seem like good ideas, but for the price of most of them motors i could go with ross and just buy one of those prius things and get like 50 mpg
I agree. Diesel is the way to go for power and economy. However, I wouldn't do a diesel swap for the sole purpose of gas mileage. A swap will cost you several grand. It's gonna take 10+ years if not more to recoup the cost of just the diesel swap with gas savings alone. Not to mention diesel is much more expensive than regular gas here in the US...