I've only had my G a few weeks and when not getting on it typically leave it in D. For the past week though I have been using DS for back roads and city streets eventhough I am driving it as lightly as when using D. I figured that with the more aggressive settings of DS and the rev matched downshifting, engine braking and so on that my mlileage would decrease. Strangely, the opposite seems to be happening. In D I watch my range steadily drop, yet in DS it seems to level off or even go up. This is when driving in the same manner in either mode. I am not driving routine routes which let me compare better due to consistency, so have to go by the range (which I have found to be fairly accurate on my car). I haven't been doing much highway travel lately, and still use D there so this is specific to back roads and city. It's a 2010 xS with about 15k so the car is well broken in. Has anyone else observed this?

 

I'd think the exact opposite - as you did. But I guess it some what makes sense if you consider the "D" mode as being a more conservative driving style mode that's more or less meant to "conserve" your engine. On the contrary, an aggressive map (DS) ups throttle response and decreases lag time; it prevents your car from going in lower gears (7th) to maintain that more aggressive response time. DS essentially decreases engine load and since it remains in a higher gear, it puts less weight on the motor...which ultimately lugs less gas; you don't have to push the car as much when it's more responsive. Does that make sense? Just my 2cents though...don't quote me on that.

 

Agreed! This is true... ey man dont you usually drive on DS?!

 

DS mode prevents the car from going into lower gears: 7th is a lower gear? I feel the opposite, when I use DS mode (and I am using that more often particulalry to obtain better response after cruising ) it puts the car into lower gear and seems to delay the upshift into a Higher gear (7th) even while on the highway at 65+ mph....after a short while at those speeds, I will see the RPMs drop to about 21,00-2,200 and know that it's 7th gear. If using DS mode and quickly downshift to next lower gear, I find that works even better, then when I hit the speed I want - shift 'er back to D mode. If I use DS mode exclusively with a new tankful of gas, MPG drops - b/c the car is generally in lower gears compared to D mode..

 

I'd like to know how you've driven 15k miles in "a few" weeks. That's alot!

 

When I say lower, I mean higher (as in 7th gear). LOL whoops

 

Ds manual mode FTWWWW.....Ill never go back to D mode again.

 

The car is new to me, but is a 2010 that has almost 13K on it but now is pushing 16k. I can't seem to stay out of it for some reason, and the miles are racking up quickly. I noticed a couple of things today. While it seems to go more rapidly into 7th gear in D on the highway, which should increase mileage there, on back roads it often seems to be in too high a gear and when I go to accelerate the engine lugs for a second or two before either shifting, or picking up sufficient revs, yet in DS it always seems to be in the right gear. This not only results in more immediate throttle response, but probably more efficiency as well. In stop and go traffic DS also slows the car more gradually. While reducing coast would seem bad for mileage, the result is that it keeps me from overbraking and again eases acceleration when traffic moves, since I am less likely to be stopped. The last tank of gas was 22.6 with little highway. I was getting 27 even on pure highway crusing between 70 and 80 today (in D of course), which I am happy with.

2010 xS w/premium and Nav

 

The TCM programming for D and DS are the SAME unless you drive "agressively".

If you drive (and brake) "conservatively", you should not be able to tell whether you are in D or DS.

 

when im in DS my average mpg plummets..

 

This is so true. I can't tell the difference but when I reset my ECU, it changes everything.