"S" for around town driving - good or bad?
 

I have the habit of putting car in "S" for around town driving, until I hit a stretch of road that requires speeds more than 45mph, at which point I put it into "D". I do this to keep revs up around town and keep car from upshifting/downshifting excessively in slow traffic/frequent stops&starts. Is this a good idea?

Thanks for your guidance.

Paul Morgan

I do this consistently as well and will generally shift up ~40-45mph. There are two primary reasons why I do this: 1. by keeping engine rev's up I believe it helps to reduce carbon buildup. 2. reduce unnecessary transmission shifts around town that, with time, could result in premature wear. Additionally, for turbo engines, the practice tends to keep the power band where it is most useful. Surprisingly, fuel mileage has IMPROVED for me with this practice.

good to hear
 

Chris,

Glad to hear my theory has merit.

Thanks,
Paul

Driving in "super" or "slope" is fine so long as you can put up with the noise and lag, its fun in the city!

Absolutely a great practice for diesels! Keep it up, your engine will thank you for it. :p

I did this for a while, but I would forget that I had it in slope when I was trying to go 70 mph on the Interstate, so I stopped doing it all together.

Hmmm....70mph would equal ~4,000 rpm - you think you would hear that with a OM617 powerplant. ;)

I would tend to notice at about 60 mph and wonder why it hasn't shifted into fourth.