4th or 5th gear better MPG

There has been a good bit of conjecture at various times about whether cruising at low speeds (40 to 45 mph) is better (in terms of MPG) in 4th gear or 5th.

I decided to do some logging with VCDS. I will refrain from posting actual results, for now, as I would really want to do some more logs, on different stretches of road, for longer periods of time/distance than I've been able to thusfar, to see if my results are consistent.

However, thusfar, my logging clearly shows, by a significant margin, that MPG is higher in 5th gear than 4th - at both 40 & 45 mph.

This is in a 2004 BEW PD manual. Flat road, no A/C, steady speed.

5th without a doubt. As load at your quoted speeds goes beyond 75 - 80% 4th comes into play.

puntmeister said:

...MPG is higher in 5th gear than 4th - at both 40 & 45 mph.

This is in a 1996 1Z VE manual, 1998 AHU VE manual, 2002 AHU VE manual, 2005 BHW PD automatic*,2004 BEW PD manual. Flat road, no A/C, steady speed.

Click to expand...

I fixed it for ya.

* the transmission controller on the auto doesn't permit 5th at 40 mph.

http://rheamp.bg/pdfs/VW-Dvigatel-TDI1.9.pdf

Page 3 - see BSFC graph.

so around 1700 - 1800 RPM is fuel efficiency sweet spot... hell even 1500 is good. I hate cruising at 1500 tho. I feel like it does the engine no good. 80 km/h (50 mph) has always been my cutoff for 5th.

6th, if you've got it. ;-)