So, I'm wondering what is the best modification to **decrease** fuel consumption?
Blackbeauty said:I hear a new exhaust makes you stomp the pedal more, but I think a Supercharger would use the most fuel! Or you could just load up your truck with 10,000 lb. That would seriously reduce fuel mileage and imcrease consumption.
Intresting. . .I always watch my RPM's and try and keep it from downshifting if I'm going up a hill, I try to keep it at a steady increase in RPMs without downshifting. . .I guess this can be called the "sweet spot" right?Steamguy said:Find the 'sweet spot' for acceleration by using a fixed RPM to accelerate and then tracking the result. (My trucks' best is 2350.) Don't just think that if you keep the RPMs under a certain level, that'll get you better mileage. You can actually burn more fuel by accelerating slower than the truck's sweet spot. That's because the throttle's open for a longer time and at a greater average opening than it would be if you just accelerated at the best rate then settled into a cruising speed. What I'm saying is there is a certain optimum RPM (hence throttle) in a hydraulically coupled system) to get to speed. This is the one thing that I've found has the biggest impact on gas mileage.
Hope this helps. :cheers:
Small hills are one thing, and yes you're right to keep your RPMs steady when going up a light grade, or even let them (and consequently your speed) drop a little. But larger hills are another thing altogether: When you're putting more than the usual power into the system such as when climbing a hill, the trans is going to downshift and lighten the top half of the torque over speed equation required from the engine to get you over the hill. As one old Master-level guy taught me: "You can't get both speed and torque at the same time. You have to choose."SeanVree said:Intresting. . .I always watch my RPM's and try and keep it from downshifting if I'm going up a hill, I try to keep it at a steady increase in RPMs without downshifting. . .I guess this can be called the "sweet spot" right?
Humm, I've never heard of a "downshift". . .is that like a chip? If not, I hear that chips will also help the engine manage the fuel intake a bit better, true?Steamguy said:At this point you really need a downshift; and that's what Nissan's done with the system. These downshifts are programmed into certain points along the power/speed curves of the engine to keep everything within the optimum range.
What I'm trying to say here is that the engine is working harder at the lower speed to get you up over the hill. Where you can notice that you're hitting the edge of the curve is when you're going say 45 and hit a fairly steep hill. The transmission will allow the engine to slow down quite a bit (especially if the torque converter's locked) before it downshifts. Let it downshift, then watch how much you're stepping on the gas. You'll notice you'll need less pressure on the gas pedal to keep it going, versus where you were with trying to hold speed in the higher gear. So in this case, by downshifting and having higher RPM, you're actually getting just a tiny bit better fuel economy. Yeah, it's now mostly disappeared because you're calling for power, but you can manage it a bit.
Hope this helps. :cheers: