ShinerBock wrote:
Adam R wrote:
but fortunately for a diesel, the difference in mileage numbers between a 200hp engine pushing a full sized truck down the road and a 400hp engine is negligible.
I would disagree with that. I would bet that a 240 hp Ecodiesel gets considerably better fuel economy than a 370 hp Cummins does pushing the same full size truck down the road. At least 5 mpg better, but probably more.
Also, I think the argument here (TnP, please correct me if I am wrong) is the fact that people saying they want more fuel economy than the power of today diesels. Basically instead of the high powered apples we are getting, they want fuel economy oranges while keeping the same power. What should be stated is that with a diesel if you increase the engines ability to use up more of the fuel's energy giving you better fuel economy, more power is also created given that the displacement is the same. Well, unless you inject less fuel per injection event. At that point, if you want to have better fuel economy while not increasing peak power then you have to decrease displacement.
I will use the Ecodiesel again. Due to the manufacturers using technology like common rail, VG turbos, electronic injectors, and more valves the 3.0L Ecodiesel is able to have the same power output of an early 5.9L 12v Cummins while having much better fuel economy. The Ecodiesel is able to burn fuel more efficiently than the old 5.9L therefore it is getting more out of each drop of fuel.
However, if you are talking about the exact same engines using the exact same technology that only gets X% of energy out of a drop of fuel, then TnP is correct that the fuel economy will not be effected negatively if peak power output is increased.
While there are similarities between a 1500 and a 3500 and may share similar sheet metal, they are not the same truck. One weighs considerably more than the other, sits taller and is built with heavier duty components. In my original comparison, of the Hellcat and Corvette, the vehicles are nearly identical but you can get a better optimized engine that will give you up to 7 mpg better mileage in each. While a 3.0 Eco Diesel can generate 240 hp, you are running it at 83% duty cycle when asking it to produce 200 hp. Yes, it can do it, but I'd be willing to bet the mileage difference between a 3.0 Eco and an early 5.9 pulling a 12,000 trailer is pretty similar. The early 5.9 is far from being overtaxed and is capably of 600 hp with a few mods. Just like the towing mileage of the 3.5 Ecoboost is apparently nothing to write home about, it's fairly well optimized for daily commuting duties. The whole reason manufacturers are going to 7, 8 , 9 and 10 speed transmissions to keep the engine in it's most optimal rpm range and hoping to eek out another 1 or 2 mpg. It's hard to compare apples to apples in these examples, but I too get tired of guys griping about "too much hp, give me mileage." If that is the case, go buy an Eco, but forget towing 18,000 lbs with it. If you want to play with the big loads, you need to buy the truck that has the grunt and chassis that has the components that will properly handled those loads with relative ease.
Just for fun, lets see someone put a 3.0 Eco in a 3500 MC and see how it does for mileage. That would be an interesting comparison.
Adam R.
