Cummins 6.7

[radman1]

I do not worry about HP anymore; I want to see torque numbers. Torque does the work, HP is a calculated number. Gas engines don't put out the torque numbers...

HP is not irrelevant. Torque and Hp are related.

Hp=(torque x rpm)/5252. There are no exceptions. This is the formula. However, torque is what gives the sensation/feel you experience during hard acceleration.
The reason the gassers pulled so well during the truck magazine comparisons against the diesels, is the higher rpms multiplied by the lower torque for the gassers. I just wouldn't want to run my engine at the higher rpms of the gasser all the time.

 

[kenmac]

It's more like bore x stroke= big bore x long stroke= torque I hapen to love torque,,,,,,,It's what moves things

 

[john_bud]

It's more like bore x stroke= big bore x long stroke= torque I hapen to love torque,,,,,,,It's what moves things

Don't forget cylinder pressure. A turbo running 30 psi boost is basically 3x the displacement of an equal engine naturally aspirated.

jb

 

[QRTRHRS]

I do not worry about HP anymore; I want to see torque numbers. Torque does the work, HP is a calculated number. Gas engines don't put out the torque numbers...

You are right on about fuel cost though. Diesel is 40 cents or more a gallon than regular in the Sacramento area. My truck gets better mileage than the previous gas trucks I had, but at 40 cents a gallon premium, gas does not look too bad now...

When I got my RAM in 2001, diesel was 10 cents less than regular locally, and I got better mileage than the two previous gassers.

Only last spring did I see diesel fuel costing less than gasoline for the first time in years around my neck of the woods. For most of the summer, it was perhaps 20 cents more but has now jumped to 40 cents more here too.

IMHO, these fuel costs have been fueling a spiraling downward economy for us and it is going to get worse. The company I drive for has gone from hauling their own products and deadheading back home to grabbing up all the backhauls they can.

 

[RobertN]

I agree it is not irrelevant. But, it is not as important to me. And, it has context. In a diesel, if I see one engine with 100ft/lbs, and another with 125ft/lbs, my interest would go to the higher torque number. Also, the higher torque number at lower rpm.

HP is not irrelevant. Torque and Hp are related.

Hp=(torque x rpm)/5252. There are no exceptions. This is the formula. However, torque is what gives the sensation/feel you experience during hard acceleration.
The reason the gassers pulled so well during the truck magazine comparisons against the diesels, is the higher rpms multiplied by the lower torque for the gassers. I just wouldn't want to run my engine at the higher rpms of the gasser all the time.

 

[cp1969]

I agree it is not irrelevant. But, it is not as important to me. And, it has context. In a diesel, if I see one engine with 100ft/lbs, and another with 125ft/lbs, my interest would go to the higher torque number. Also, the higher torque number at lower rpm.

By going with the higher torque number, you are also going with the higher horsepower number. Not peak horsepower; but available horsepower at low rpm is higher with the higher torque value. HP=torque x rpm/5252 throughout the rpm range. If an engine has more torque at low rpms than another, it has more horsepower at those engine speeds.

If you were to overlay the the HP curves for a diesel over that of a gas engine, you would see the diesel has more horsepower down low.