Success!

[herschen]

I have been changing up my commute, using FAS down hills, using CC up hills, and using P&G in flat areas. I usually shut off the engine when I P&G at a slow speeds (below 30mph), but at higher speeds I usually just set the CC at the highest speed that I will be doing and then coast with the car idling and then click the resume button to accerate back up. I use this technique due to several factors: I am lazy, I have a manual transmission and CC resets every time I kill the engine, and I can't really hear when the engine starts at this speed. This is also the main technique I use at night when I don't want my lights to shut off when I kill the engine.

My car is rated for 21mpg city 28mpg hwy...I got 42mpg. I saw someone got 50 mpg in another Golf; I'm content with this for now.

I read that the ideal speed for fuel economy is 38 mph. Is there a different ideal speed depending on the grade of the hill? (I usually try to get to the speed limit before I hit the hill and then use CC). Does P&G work on hills? Will I kill the battery shutting off the engine (the lights are automatically on)?

[Right Lane Cruiser]

Congratulations!!

38mph sounds pretty close to correct for a flat, no incline road. The ideal speed for an uphill is usually lower, and you can do better yet if you slowly bleed off speed while ascending. Rolling hills that are not too high can be great for fuel economy using a variation on P&G -- the best are the ones you can give just a little pulse just before the crest of a hill, then glide to the same point on the next hill, etc. I've seen highway speed numbers up into the low 60's in my Elantra over such terrain.

You do need to keep an eye on the battery voltage if you are FASing with the headlights on. You don't want to let that get too low! The ScanGauge can monitor that for you (showing it as one of the gauges). If you do a lot of this you may want to consider getting a beefier (deep cycle) battery to handle it. I installed an Optima Yellow Top and though it was really expensive, it has been so worth it!

[laurieaw]

very good improvement!

[atlaw4u]

That makes me smile.

[2003protege]

good job! ...it wouldn't let me just post "good job!" so i'll say it again. good job!!!

[Shrek]

Originally Posted by Right Lane Cruiser

Congratulations!!

38mph sounds pretty close to correct for a flat, no incline road. The ideal speed for an uphill is usually lower, and you can do better yet if you slowly bleed off speed while ascending. Rolling hills that are not too high can be great for fuel economy using a variation on P&G -- the best are the ones you can give just a little pulse just before the crest of a hill, then glide to the same point on the next hill, etc. I've seen highway speed numbers up into the low 60's in my Elantra over such terrain.

I find it sometimes a bit easier to climb long hills at constant speed, and then let the speed start bleeding off when I get closer to the top. I wonder how that compares to letting the speed drop over the whole hill.

I'd imagine it being better to have 75% engine load for 80% of the hill and idle for the last 20%, rather than 60% from bottom to top, as you might have in the slowly bleed off speed case?

[Right Lane Cruiser]

Shrek, that depends upon how tall and steep the hill is. Unless the hill is short you'll end up having a minimum speed you have to consider safe. If no one is around, that could be crawling. Regardless, you'll hit that and then just drive constant speed up the rest of the hill.

The slowly bleeding off speed mileage is higher than the constant speed average in every case. It may not be a whole lot if you are bleeding off slowly, but it is still more. Averaged in with the constant speed for the rest of the hill (if you actually have to get to that point) it will pull your mileage up from simple constant speed climbing.

I hope that was clear?