Quantitative Pulse and Glide

Good testing is based upon holding as many variables constant and only changing the one under question. Certainly it is important to document the methodology to so others can replicate THE RESULT. Sad to say, we get a lot of "Pulse and Glide" methodology and too little test results where everything is kept constant except the use of "Pulse and Glide" versus say "constant equivalent speed."

On a single day I conducted a series of runs over the same course, both ways, only changing:

o pulse and glide o constant speed

PROTOCOL

Pulse was handled by using "resume" on the cruise control stalk. Glide was handled by shifting into "N". This limited the speed range to

25-42 mph due to the 23 mph lower limit of cruise control memory and upper limit of 41 mph on hybrid mode.

Constant speed was handle by setting cruise control to the equivalent, speed over the course of the pulse and glide protocol. Entry to the course was at the constant speed equivalent. Exit was at a fixed location at least six pulse and glide cycles later.

RESULTS:

constant - PnG

70 - 78 74 - 85 76 - 90 85 - 93 90 - 94

- - - - - -

79 - 88 MPG average

PnG = 11.4% improvement

So for the pleasures of changing the speed from 25 mph to 42 mph, mileage improved 11.4%. Sad to say, I've only found one other similar report, SAE 2009-01-1322. However, it looks like they allowed the traction battery SOC to decrease during some of their tests. Still, we have two documented tests comparing PnG to constant speed.

. . . Anyone else?

Bob Wilson