Horsepower and Fuel Mileage.

I didnt vote because I only have an opinion based on old school fundamentals. I can see this post getting so many different opinions based on equally as many factors.

The adage that a larger, stronger motor will work less doesnt make sense to me because in order to make that HP it needs fuel. Yes it will climb the hill quicker,.. but at what cost?

Thats only my opinion and not based on fact. I am mechanically inclined,.. but would not classify myself as a tech or diesel mechanic.

Smaller engines that are built (Internally) to handle the stress of making big hp should in my opinion offer the power and reliability needed while using less fuel.
Typically if you are hauling that heavy, fuel economy is not a detrimental factor as you should be paid enough to compensate.

I am very curious to see what others have to say on the subject.

Hurst

 

You forgot mechanical Caterpillar on the list so I couldn't vote honestly.

I'd even settle for a computer CAT.

 

BTW if it takes 245 hp to move a rig down the road at 60 mph, a 290 Cummins and a 600 CAT are both going to use 245 hp!

The difference is if each engine is set up to run at it's peak efficiency and maximum power.

You have several hp ratings of the same engine listed. Obviously the lower rated ISX and 'roit engines aren't all they could be. Why even consider them?

 

Yeah, did not see 6NZ CAT, so could not vote.
But assuming he is buying newer where yellow is not a option.

Am interested to see where this goes. Have had the same guy tell me that 600 hp saves fuel, then later in the conversation talk about air fuel ratios & power costs money.

All I know is my stock 2KS CAT C12 is good on fuel, but needs more power.

 

I used to baby my 430/470 detroit when heavy and still ###### mi. Had rebel127 tune it to about 550 and I get awesome mi even when I hammer it on every hill or run it to 2400rpm just to feel it push me back in the seat going through the gears.

 

I don't think there is one clear answer to this, as is a combination of the engine as well as how you drive that engine.

On the flats the smaller engine will save you more fuel in my opinion as it is capable of producing the same power as the larger engine (when you aren't making it produce at 500+ HP). Going up a hill the higher HP engine will likely give you better mileage but what you have to balance out is, am I on the flats traveling at speed for the majority of the time or am I going up hill or accelerating for most of the time. You can take a lower power engine and be fine to say I will take an extra 30 seconds to get up the hill out of the river valley and probably get the same mileage.

At 63.5T, no engine is going to get up a hill without breaking a sweat, some will do it a little less than others but overall they are all going to be working. The mountains are something different, but in my opinion 500HP is good for the prairies, it wont cut it in the mountains but its also knowing the limitiations of what can happen at that weight. For some it is a measuring contest and wanting to be able to beat a car up a mountain. My first mountain trip with my dad we were going up the Salmo Creston. I went to take a nap at the bottom and woke up before we got to the top and was shocked it took that long.

You really need to buy 10 trucks with different engines and setting and figure it out that way. If only the trucking magazines would do that and not just right fluff articles on every truck they test about how wonderful it was.