i’m rebuilding an old jeep, i was able to take alot of the weight off. i don’t really care about performance, horse power, and i’m not planning on taking it on the highway, all i care about is mpg, but i heard that the smaller diesel engines are less efficient than the big diesel engines, is that true, and which would be better for the jeep’s mpg?
Tags: Diesel, efficient, Engine, light, More, small, than, weight
It really depends. It’s possible to put an engine that is too small for the size of the vehicle, in which case it will have to work really hard just to keep it moving and you will get poor fuel economy. For the jeep, it’s pretty light. I think it would be hard to find a diesel engine too small for it. A bigger engine will probably get worse fuel economy. If all you care about is mpg, get the smaller engine. As long as it’s not like a tiny engine from a lawn tractor or something it should be OK.
Angel a jeep in general is to lacking in aerodynamic design to get top fuel millage. Now lets talk power to weight ratio’s. a 10 wheel tractor will get a slight benefit when running at 55 miles per hour from a smaller engine size as long as he pulls no hills and does not need to stop and go. his issue is more weight than power. a truck the same size etc but running a far stronger motor will be easier on the drive train when pulling out from a stop and will take the hills at speeds well above the smaller motor. the smaller engined truck will be down shifting to hold a speed of say 25 miles per hour and have the pedal l mashed down. the larger truck will clear the hill sooner and likely not be pressed to the floor so he will save in fuel over the smaller engine. so the answer is? a big enough engine to keep it at highway speeds without being floored and gearing to utilize the power most efficiently.
Strictly speaking, larger engines are more efficient than smaller ones. But for what you want, you don’t care about efficiency, you care about fuel utilization. A smaller engine will use less fuel unless it is struggling with a lot of weight, which you aren’t. Case in point, my Jeep with the small 2. 8 engine got 22MPG on the highway, but when I pulled my boat it dropped to 12 MPG and barely kept up to speed. My newer JEEP with the 4. 0 engine only gets 20MPG on the highway, but when I pull my boat I still get over 18MPG. If you are going to be driving on dirt roads in 4WD a lot a small diesel will do you well. Just don’t try to take it on the highway!
Yes it would be because of the torque it will not take as much gas to move the vehicle so even if it has the same horsepower the larger engine will have more torque and be more efficient in the same weight of car or truck.