Super-Stormtrooper07

I may also post this in the xA forums, but figured I'd get more of a response here.

What is everyones take on the "Pulse and Glide" effect? You know, when your on the gas, then you take your foot off the gas to then conserve a bit of gas, then your back on it(like a yo-yo) ?

How much does this really conserve gas ?
Also, I'd think that by having a steady stream of gas feeding your cylinders would put less wear(and would increase longevity) of ones engine (possibly the tranny as well).

Any info ??

kmx22

well, once you get the car going and let ur foot off the pedal, there is not gasoline going into ur cylinders. the gasoline produces combustion, not a lubricant. that's why there is an oil pan under ur pistons to lubricate them.

as far as saving gas, it depends on how much ur doing it. if ur gliding from 60 to 30, and then shooting from 30 to 60 to glide again, i don't think ur doing anything. but every downhill or like 5-10 mph of gliding would do good. but that's just my perspective.

SentraSE-R

I've installed a Scangauge II on my xB (manual transmission) and have tested its fuel consumption at different speeds.

Steady speed cruise control & mpg
70 mph = 32 mpg
55 mph = 39,7 mpg
50 mph = 44.9 mpg
40 mph = 49 mpg
35 mph = 52.9 mpg
30* mph = 51.6 mpg

*4th gear

P&G between 48 and 60 mph typically gets me about 52 mpg
P&G between 25 and 40 mph can get me 60+ mpg

You're getting about 20 mpg during a moderate acceleration, but 200+ mpg coasting (if you're not in gear). If you can coast twice as long as you pulse, the math is definitely in your favor.

Our xAs and xBs have deceleration fuel cutoff at 1500 rpm or higher, when your throttle position sensor is in idle position and you're in gear. Otherwise, you're burning fuel when the engine is on.

The best things you can do to improve fuel consumption are to slow down. and avoid jackrabbit starts.

SentraSE-R

Short trips kill mileage. The reason I don't average 50+ mpg is short trips where my mileage never gets over 35 mpg.

Zman

P&G is an effective technique. I typically don't get to drive on flat roads so I glide (in Drive or Neutral) down hills only. It's best to slow down but to maintain enough speed to use your final gear.

Yesterday on I-68 coming from Morgantown the Scanguage read ~20mpg @ 55mph uphill in 4th gear and ~14mpg @50mph when I had to drop to third gear. Some of the hills are so steep that the poor ol' 1nzfe can't handle it unless you're around 4K rpms.

Downhills in neutral yield anywhere from 100mpg to 500mpg depending on speed.

Super-Stormtrooper07

I'm picking up what your all throwing down.
To narrow in on my question a bit, could I get some feedback when using P&G on a flat roadway(so in a perfectly flat road environment). Would P&G be benificial from time to time .... or would it be best to just have a feather-foot and have a constant stream(however small) of gas igniting the cylynders?

SentraSE-R

P&G beats steady speed on the flats by about 3-5 mpg. If I'm on a long straight stretch of road averaging 45 mpg at 50 mph with cruise control, I can raise it with every P&G cycle until it tops out at about 50 mpg, averaging the same 50 mph.

Conversely, if I'm averaging 50 mpg on the same road with P&G, and get lazy by setting CC, my mileage will steadily drop until it levels out about 5 mpg less, at about 45 mpg.