Diesel vs gas......................

transamz9 wrote:
I'm not trying to be a pain in the *** but I am like you trying to get as much of the info on this thread correct. First off Taco I'm sorry, I didn't catch the "I" in the post where you said that it would cost "you" 14-15G more. I'm sorry for that. So you bought a half ton instead of a three quarter?

As far as routine maintenance cost go, yes if you buy a Ford diesel because they have to until they get the bugs worked out. The others, I don't think so.

OhhWell, I know that torque is stationary but here's my theory. You guys have already said that a diesel will get up to speed quicker with a load because of the low end torque. If you think about it , it makes sense if you have 600 lb/ft of pressure trying to turn a wheel as apposed 300 lb/ft of pressure trying to turn a wheel. Same as true if you are already running a set speed (flat ground) and you start up a 6% grade. It's going to be harder to slow a wheel's speed down that has 600 lb/ft then it will 300 lb/ft.

Am I thinking correctly?

Not really. The engine torque does not directly turn the wheels. It is fed through a transmission. This means the higher torque engine will deliver more HP to the wheels only if the 2 setups have same rear axle gearing and are operating in the same tranny gear. Practically, this gives the higher torque motor an advantage off the line. But once moving, the high torque (low rpm) engine will need to shift sooner. Shifting up proportionally decreases the torque applied to the rear wheels and you're soon back to the same wheel torque that the low torque engine is providing.

The torque at the wheels applied at a certain speed (wheel rpm) is the horsepower being delivered. The engine that can maximize the HP delivered to the wheels throughout various gears and conditions will pull harder. If both engines produce the same HP within the rpm band they operate in between shifts, they will perform the same. Gas engines don't pull hard at low rpm when first taking off or if run in too high of a gear. This was the issue with 3 and 4 speed transmissions. Too often the gas engine was shifting from a rev limiter to below its HP producing rpm range. With 5 and 6 speeds these days the problem is all but gone.

The reason earlier generation diesels "worked better" is because people didn't want to have the gasser cranking out the high rpm needed to produce its peak power or the transmission didn't provide the proper gearing. Gassers also don't have the benefit of a turbo so they lose HP at high elevations.

The newest diesels pull harder simply because they are producing more HP than the gas engines.