HP vs Fuel Mileage

This is kind of a trick question.

When my motor was stock it got bad fuel mileage. Once I turned the fuel to it, it went up.

With that being said, it also depends on the driver.

 

Im gonna assume the shaker you had was powered by a detroit. They are known for getting better milage. Mine is a 515 detriot and I get about 5 with it but I run in the mountains of PA all the time and its geared lower and I run 72. In 8 over at 72 my rpms are about 1650-1700. I may have a 515hp but I get walked all over by the 475 cats even when they are heavier, but the cats do get worse milage then I do.

 

Of course! If you are an experienced driver with more power you will get better fuel mileage. Now this is true for the folks who travel 48 states. If you are just toodling around Florida then it probably won't work to your advantage. You burn up a lot of fuel spinning those low gears chuggin up the big hills. If your truck has more muscle to put behind the bigger gears then you can go up these hills without having to keep dropping little gears. The down fall is inexperienced drivers don't know how to shift or even why they are shifting! Also, they would burn up all their fuel trying to race everyone from light to light, basically using up fuel at the wrong times. The lowdown, experienced drivers can do very well with a little more hp. Overall for large companies though it is way more economical for them to run with no "balls".

 

I have a 600 cat and get 5.8 to 6.3 mpg with it runninmg the northeast at 80k with about 25% empty and i know guys with smaller hp Detroits,cats and Cummins that only get in the low 5s. Alot of it has to do with the way you drive,the way your truck is speced plus the area you haul not just the size of your motor. But for me i will take a big hp motor anyday over a small hp one. Its not hard to figure out a big hp motor will do better on fuel if speced and driven right just because it will turn less rpms to do the same job and pull a hill with less strain.

 

I can understand progressive shifting in most situation's but I'm sorry your not going to progressive shift taking 6 months to get through a large intersection with a 10 second green light and a #### load of traffic.

 

My 3406E (435 HP) has a lifetime ECM mileage of 6.23.

Last week, running two loads at over 50K in the box, I got right at 6.5. I just did a major on it in September.

My son's 600 CAT in his 379 can get 6+ if he keeps his foot outta it... but his hired driver can't seem to understand that.

The 12.7 Detroit in his 377 gets a steady 7.2 to 7.4 with him behind the wheel.

 

I'll take horsepower, thank you. Less HP means my foot is goung to be in it a lot more.
Also rear gearing has a lot to do with it.

 

The truck I drove with a Cat C15 set at 550 averaged 6.75 to 5.25 running 11 west same as now, the truck I currently drive has a 450 Detroit that only averages 5.75.

Both 10 speeds.