P&G on CVT-any real benefit

[Titan]

Im a newbie to the I1 but not new to hypermiling. Thru the first 600 miles I have averaged 60.1mpg. I do the same route to work every day and noticed when I just set the cruise at 60mph or P&G up to about 61-62 then glide back to 55, and repeat I see NO appreciable change in my mpg, for a 60 miles round trip. Im questioning weather P&G for a CVT is a smart thing to do based on how the transmission works ( Im not an expert on the how the CVT works) just guessing that Im unloading the trans during glide. The gliding may be causing trans slipping and then re-engaging during the pulse causes more direct drive, so that might be defeating the whole purpose of P&G and thus the reason why the MT have a such an advantage with P&G due to direct drive?

Who has good results from P&G with a CVT, verses just cruise control at a moderate speed?

[Cobb]

I find most of my success with the i2 is between 45-20mpg shifting to nitral and coasting.

[Titan]

Im thread jacking my own thread LOL. We had a bit of heat wave here in MI this week and its in the 70's. My mileage is wayyy up. I can easily touch 70mpg in the 45-50 mph range. I couldnt do that when temps were in the 30's and 40's...time for the hot box mod!

[Cobb]

Yeah, these cars seem sensitive to the heat and I am lucky to break 150 degrees engine coolant temp in stop n go driving with auto stop working each stop. I got 3/4 of the lower grill blocked off and it hovers between 179-181 degrees.

[nayrhyno]

Originally Posted by Cobb

I find most of my success with the i2 is between 45-20mpg shifting to nitral and coasting.

Not sure what you mean by 45-20mpg, maybe mph. But shifting to neutral to coast is bad for the CVT. It has been discussed many times. If you are coasting in neutral you should not be going back to drive at any speed greater than say 4mph or you will cause excess wear to the start clutch.

As far as the OP, I get good results with "pulse and glide." To me, it is just the normal way to drive. I try to scrub speed going up a grade and pick it up going down. I also try to "pulse" at about 60 mpg on the instant FCD meter, i.e. two bars above the 50 mark. On flat ground, if my speed drops to 52-54 I put the FCD at 60 mpg until I hit say 57-58, then back off to 75mpg on the FCD. Obviously I need more gas to make it up some hills or to start from stop or accelerate when changing speed limits, but that's the general idea. I don't have cruise control, but when I do drive in traffic and need to keep my speed more constant at 56-58 to feel safe, I notice a significant dip in MPG.

And yes, temperature makes all the difference. A scan gauge to read the actual coolant temps and an adjustable radiator block will help a lot.

[Cobb]

Opps, yeah, mph not mpg. Ive tries it at various speeds, seems works best on back roads. I hate it when you shift back to drive as it seems to take a lot of throttle to get the engine to accelerate and after 3 coasting events you end up regenning the 4th try.

Yeah, I like just driving like I am a big truck. Slowing up on hills and speeding up going down.

If I am behind a large semi I like to speed up to their bumper, then coast down http://www.youtube.com/watch?v=5P41B-jSG-U

[dirty hippie]

What exactly is Pulse and Glide? I've read about it in the various hypermiler sites but still not sure what it is, or if I'm even doing it when I drive.

I have a CVT, and when I see a red light or a light that's about to turn red, or when I'm anticipating a stop, I will let off the gas pedal and let my car cruise as it slows down. All the while the FCD pegs to 150mpg. If my car has lost significant speed before I near the stop point, I will tap the gas if a car is behind me (so as not to annoy the driver) otherwise I will slowly "glide" to a stop.

Is this P&G?

[MN Driver]

No, pulse and glide is where you give the car roughly ~90% load(not to be confused with throttle position) and accelerate to a target speed, put the car in neutral, coast down to a lower target speed(say 10mph slower), start engine(or blip clutch), speed up to the initial target speed and continue this process. While coasting with the engine off and in neutral, no gas is used and the engine isn't being a hunk of recipricating drag and pumping losses. While under load it is more efficient than operating a constant lower load. This is why smaller engines get better fuel economy, they operate at a higher load. The idea is to put as much of the air being pumped through the engine to good use at its most efficient point. It's easier to do and most beneficial at lower speeds(50 or less) where the engine would otherwise have less load and car would have less drag to slow you down between pulses.

The question at hand is how the CVT reacts to this, not sure if it enjoys being put in neutral and back into drive repeatedly. Also not sure if its possible to pulse with enough load because the CVT might just decide to raise engine speed to keep the load down or provide the performance it things you want with that throttle position. Without being able disabling the electric assist, if you are using assist when pulsing your gains are down the drain. I wish I had a CVT to try to at least see how it reacts to acceleration with the assist and gear ratio changes but I'm a little short on knowledge because I can't compare. Does anyone with a CVT have a Scangauge that can monitor LOD and tell me how the car reacts as far as engine speed and assist go for 85% LOD and 90% LOD. I usually pulse and glide in the low 90% range LOD but that's the point where if I didn't have a clutch switch I'd be in the high 80's which is about where lean-burn sits too.

[dirty hippie]

Originally Posted by MN Driver

No, pulse and glide is where you give the car roughly ~90% load(not to be confused with throttle position) and accelerate to a target speed, put the car in neutral, coast down to a lower target speed(say 10mph slower), start engine(or blip clutch), speed up to the initial target speed and continue this process. While coasting with the engine off and in neutral, no gas is used and the engine isn't being a hunk of recipricating drag and pumping losses. While under load it is more efficient than operating a constant lower load. This is why smaller engines get better fuel economy, they operate at a higher load. The idea is to put as much of the air being pumped through the engine to good use at its most efficient point. It's easier to do and most beneficial at lower speeds(50 or less) where the engine would otherwise have less load and car would have less drag to slow you down between pulses.

The question at hand is how the CVT reacts to this, not sure if it enjoys being put in neutral and back into drive repeatedly. Also not sure if its possible to pulse with enough load because the CVT might just decide to raise engine speed to keep the load down or provide the performance it things you want with that throttle position. Without being able disabling the electric assist, if you are using assist when pulsing your gains are down the drain. I wish I had a CVT to try to at least see how it reacts to acceleration with the assist and gear ratio changes but I'm a little short on knowledge because I can't compare. Does anyone with a CVT have a Scangauge that can monitor LOD and tell me how the car reacts as far as engine speed and assist go for 85% LOD and 90% LOD. I usually pulse and glide in the low 90% range LOD but that's the point where if I didn't have a clutch switch I'd be in the high 80's which is about where lean-burn sits too.

Thanks, now I get P&G! I don't think I would feel very comfortable shifting an auto/CVT from D to N when it's in motion as if it were a manual.

On the other hand, I wonder if what I'm doing is okay for the engine by letting it coast to a slower speed or stop and lugging the engine.