Been doing some research on used trucks and i was wandering if high horsepower was a good thing or bad??

I was thinking and its really dependent on where you drive and the terrain where the truck is operated...

i see a lot of 430HP trucks, couple of 470 and a rare 500HP engine but what would be the most bang for the buck considering MPG?? I was trained that going low and slow would be the safest but would that be more fuel friendly???


any comments would be appreciated

Contrary to popular belief, horsepower nor torque point to fuel mileage. The type of engine(brand) has more to do with it. Having higher or lower HP does not affect efficiency.

Going slower is always more fuel friendly.

The most fuel efficient engines are usually the smaller ones(11-12 litre).

Where you drive and weight you pull will determine HP IMO.

We had a 500 Detroit with 1,000,000 that got better mpg's than a 475 C15 CAT with 500,000.

We have a 410 N14 that will hang with the Cat on the hills.

We have a sub 400 hp M11 that will hang with all of them on the hills...but it has a 4.11 rear and it's screamer on the flats.

Depends on what kind of work you do, I just ordered a new kenworth and I put a 470 hp C13 engine in it rather than a C15, not only is it more fuel efficient, but it is 500 lbs lighter. I don't need big horsepower for what I do, which is hauling dryvan.

You don't need big horsepower, except for heavy hauling applications,

I say it how its driven, my 600HP Cat can and does get in the high sixes, if I drive it a little more conservatively, although mid to high fives is the norm.

Basically its all up to the driver........and how its operated, nothing else.

Exactly, if you took that engine and replaced it with a 475, you might get EXACTLY the same fuel mileage. Down to the 1/100th.

However, if you regularly used that 600 HP to go fast, and accelerate needlessly, you'll see a huge difference!

Adding to the above posts, I believe the right tans mated to the right engine is part of the equation. This is linked to what you haul, aslo, and where you haul.

I get 5.5 out of a 550ISX at 73,000lbs and 70mph with minimla wind in a KW T600 without the sleeper top fairing and no nosecone on th trailer.

Just for contrast, I get 6.5 mpg out of a 465 HP N-14 at 77,000 lbs and 65-75 mph with minimal wind in a KW T600 with the sleeper top fairing, and no nosecone on the the trailer.