C15 Cat and ISX Cummins
 

I am trading my truck in for a newer one. I am tired of my Detroit series 60. Which of the 2 engines would you prefer?And why? What are your experiences with each one?Good and Bad? What kind of fuel mileage have you gotten with these engines at speeds of 85 to 100mph?

IMHO at those speeds, you shouldn't bother about fuel mileage, it's not gonna be good with any type of an engine.

You must have some really tight delivery schedules. Is it mostly city work as well? :D

No,I just like to drive fast.:D We don't have to answer the last question yet. So who has experience running any of these engines?

I do.

Last 2 motors were C-15's. I get about 5.3 at excessive speeds, and 5.8 at normal speeds. Happy overall with performance. I have never owned a Detroit though, so I can't comment on them.

Okay Triple Digit, I'll try to help you out with my first post on here.

I've driven a lot of Cummins that I liked and only one Cat that I liked--it was a 550hp. It seems like the other Cats I drove, that were below 500hp, couldn't keep up with a Cummins.

I say stick with the Cummins. I am curious to hear about the new International 600hp engine, I kinda think that thing might be hoss.

Sounds like you may be making some of those Western reefer runs at the speeds your running. I used to love running out to LA from home (New Orleans). I-10 will make you love a fast truck.

The company that i work for has all 475 and 550 cats that run pretty good .My boss just got a good deal on a 06 pete with the 565 cummins .When we are on a hill the cummins just walks away from the 550 cats .I have to admit the cummins runs better than the cats we have.I cant comment on fuel millage because we do all heavy haul in excess of 120,000 lbs.and the fuel millage on both motors are bad.

Same gearing?

Yes they have 411 gears with the 18 speed.I was suprised myself always thought the cats pulled better.The company has always bought cats but they are really happy with the cummins.The only differance is the cummins is a 2006 pete and the cat is a 2004 kenworth.