I often do this in my Micra 1.0 when stuck behind slow lorries on rolling roads. Pop her in and out of 5th gear at 40mph to save a tiny bit of resistance, although the engine runs quite free when warm. Not worth doing at much above 70mph though unless I have a tailwind. I also do this on downhills when I want to go a bit faster than coasting allows. Make the speed range smaller to improve efficiency as wind resistance increases as speed squared, so sometimes you may be better off holding steady.
This technique is almost equivalent to giving your car an extra high top gear. If you had an extra tall (80mph 2k rpm) gear then steady state would be fairly similar mileage I reckon. You are getting best fuel to power conversion at 2k rpm floored accelerator in most diesels. This gives too much power for a moderate cruise though in all but the smallest engines.
At high speeds in a diesel (looser engine because of less pumping losses) with taller gears, the technique is less effective. 80mph is also bit fast to bother using the technique because of the extra wind resistance. On a large engined (V8 or more), low geared, streamlined car, this technique could save quite a bit of energy by meaning you don't have to fight engine braking your whole trip. An Ultima GTR is one car this would work well on, though the pulses would be fierce even at 2k rpm!
If I hear funny noises I just turn up the radio. Car is still going strong though, over 500K miles now. And I put in a .658 5th gear sometime after that video. Managed to get 1000 miles on three straight tanks of fuel with easy highway driving. But, using the car more like a work vehicle these days, more city driving..
I use a live OCB2 WIFI connection to my iPad and can see what draws fuel. When decelerating (in gear) the fuel flow is ZERO. On a 400Km road trip (over the mountains) I recorded an average (uk) mpg of 57.3 or 47.7 mpg US - 2010 Jetta TDI.
you're doing it wrong by putting the clutch in/shifting into neutral. While idling an engine uses some fuel to keep itself turning over whereas if you coast down in gear you are using no fuel whatsoever,
I'm pretty sure that accelerate and decelerate continuosly it's not the best way to save energy (fuel). 1. soft accelerations - 2. "constant speed" - 3. use the inertia more as you can. (PS. put the safety above everything else)
***** I guess the only way to explain this would be due to less energy loss in the engien it self. The energy loss due to drag and friction would remain the same, but friction in the engien at 1000 rpm is lower then at 2000 rpm. However energy loss in due to transmission is only a few percent at this speed i guess you could save a litle bit by doing this. Atleast thats what i can make out of puls and glide. btw, if it would be possible to turn of the engien totally during your glide you would save even more, how ever this is really dangerous!! (excepts in hybrid vechicals)
55 mph is most fuel efficient speed. I pulse up to that speed and glide. In km/hr I pulse up to 100km/hr and glide back down to 80km. For those naysayers.. They can continue paying high fuel prices! Pulse and glide whileever you have a combustion engine. Want smooth driving? Buy an electric car!
f4ll0wf1r3 Not true. It really depends on the car. Going from purely a fuel effiency point of view, the speed is usually 35-55km/h (usually belowe 45km/h).. You can get to below 3l/100km when driving with like the 5th gear and at 40km/h on a 1.9 TDI and the more aerodynamic VW bodies.
I often do this in my Micra 1.0 when stuck behind slow lorries on rolling roads. Pop her in and out of 5th gear at 40mph to save a tiny bit of resistance, although the engine runs quite free when warm. Not worth doing at much above 70mph though unless I have a tailwind. I also do this on downhills when I want to go a bit faster than coasting allows. Make the speed range smaller to improve efficiency as wind resistance increases as speed squared, so sometimes you may be better off holding steady.
This technique is almost equivalent to giving your car an extra high top gear. If you had an extra tall (80mph 2k rpm) gear then steady state would be fairly similar mileage I reckon. You are getting best fuel to power conversion at 2k rpm floored accelerator in most diesels. This gives too much power for a moderate cruise though in all but the smallest engines.
At high speeds in a diesel (looser engine because of less pumping losses) with taller gears, the technique is less effective. 80mph is also bit fast to bother using the technique because of the extra wind resistance.
On a large engined (V8 or more), low geared, streamlined car, this technique could save quite a bit of energy by meaning you don't have to fight engine braking your whole trip. An Ultima GTR is one car this would work well on, though the pulses would be fierce even at 2k rpm!
Save gas. Buy clutches.
Not on hybrids
I turned a 5 Liter/100km car into a 2.5l/100km car :D
Just wait til this guy hears what a clutch release bearing is.
If I hear funny noises I just turn up the radio. Car is still going strong though, over 500K miles now. And I put in a .658 5th gear sometime after that video. Managed to get 1000 miles on three straight tanks of fuel with easy highway driving. But, using the car more like a work vehicle these days, more city driving..
@@mddorogi I just think it's better if you switch to neutral when gliding. If you learn to double clutch, it will barely do any wear to your synchros
@@user-vs7sb9wg2rNeutral or depressed clutch means you re gliding with an idling engine.
And it looks exhausting to do that all the time
I use a live OCB2 WIFI connection to my iPad and can see what draws fuel. When decelerating (in gear) the fuel flow is ZERO.
On a 400Km road trip (over the mountains) I recorded an average (uk) mpg of 57.3 or 47.7 mpg US - 2010 Jetta TDI.
Peter Piper Yeah, but when idling the fuel consumption is also
indeed!
But you can coast further in neutral vs engine braking in gear. The 2 are both about the same in terms of economy
Yeah but in neutral the engine is idling . Still some fuel consumption
burning clutch too much
The speed drop isn't that fast, not as annoying as someone jamming their brakes on in front of you!!
you're doing it wrong by putting the clutch in/shifting into neutral. While idling an engine uses some fuel to keep itself turning over whereas if you coast down in gear you are using no fuel whatsoever,
I'm pretty sure that accelerate and decelerate continuosly it's not the best way to save energy (fuel).
1. soft accelerations - 2. "constant speed" - 3. use the inertia more as you can.
(PS. put the safety above everything else)
***** I guess the only way to explain this would be due to less energy loss in the engien it self. The energy loss due to drag and friction would remain the same, but friction in the engien at 1000 rpm is lower then at 2000 rpm. However energy loss in due to transmission is only a few percent at this speed i guess you could save a litle bit by doing this. Atleast thats what i can make out of puls and glide. btw, if it would be possible to turn of the engien totally during your glide you would save even more, how ever this is really dangerous!! (excepts in hybrid vechicals)
When pulse, you are in the efficient zone of your engine according with BSFC maps, that's why you have better fuel economy when pulse and gliding
55 mph is most fuel efficient speed. I pulse up to that speed and glide. In km/hr I pulse up to 100km/hr and glide back down to 80km. For those naysayers.. They can continue paying high fuel prices! Pulse and glide whileever you have a combustion engine. Want smooth driving? Buy an electric car!
f4ll0wf1r3 Not true. It really depends on the car. Going from purely a fuel effiency point of view, the speed is usually 35-55km/h (usually belowe 45km/h).. You can get to below 3l/100km when driving with like the 5th gear and at 40km/h on a 1.9 TDI and the more aerodynamic VW bodies.