[cbaber]

What I've found is that it's better to accelerate at 70-80% load and then focus on DWL, than try to accelerate gingerly. Since your on a vacuum gauge you have to translate my numbers to the appropriate vacuum equivalent, which Pale already mentioned was ~5-10". Also keep in mind that for any given speed, the higher gear (lower RPM) is more fuel efficient than the lower gear (higher RPM) assuming your staying within the 70-80% load range we discussed. It may seem natural to downshift when your RPM's are around 1500 and your vacuum gauge is really low, but its still more fuel efficient to drive at high load and low RPM than lower load at higher RPM at a given speed. Basically, unless you are having to go WOT, stay in the highest gear possible and keep your shift points low.

If I am city driving I do by best to time lights. If I am accelerating from a red light I need to know my situation up ahead. If I need to stop again, or slow down, I will accelerate 70-80% load and then neutral coast or EOC sometimes. You still want to follow the rule of driving without brakes (DWB), and when you need to accelerate do so at your engines highest efficiency.

On the highway the goal is to use the least amount of power possible to maintain speed. This is load driving. For my car and my commute I plan out the engine load for each hill so that my speed tapers off slowly. If I were to hold my speed it would require a higher load, using more gas. If I taper my speed off from 60 mph to 55 mph in the duration of the hill, I use less gas that way. On the other side of the hill I can make it up using gravity as an aide.

I don't like to slow down too much, though. I've found that if I take off too much speed up a hill, I am having to use more load down the hill to regain speed. Instead I only allow 5 mph to taper off, and then I can quickly get back to up 60 mph and use very little load to go down the hill (or sometimes EOC).

I see massive swings of engine load (or vacuum in your case) when driving over different terrain. Up the steepest grades in my area I have to use 70-70% load just to maintain speed. On downhills I only use 25-35%. Below 25% is idle basically. Flats are 35-45% load. It's so nice to have a Scangauge that can tell me engine load, as well as the MPG I am getting at that load.