: Sport mode and gas efficiency



flycaster
04-24-13, 03:19 PM
Of course, when put into sport mode, one is going to push the car. Which in turn will up the gas consumption. I'm trying to get the feel of my 2002 325i out of the ATS, particularly tighter steering, by driving in sport mode. When driving in city type environment, would I be correct in that sport mode would hardly be felt? Although the ATS does hold the road nicely, I don't think it will ever give one the road feel that the older (pre-2007) BMW 3s do, but what about the steering. Under tour, I find the steering to be OK, but not tight. Switching to SM, the steering doesn't seem to do anything at "city" speeds, and does seem to tighten up a bit under highway conditions...but not all that tight. Holding gears in SM does work, as up/down shifting. So, assuming one is in SM, but not pushing the car, what kind of changes in gas sonsumption can one expect?

gfxbt
04-24-13, 03:52 PM
I wondered this myself, so on my last trip that was greater than 50 miles, I drove one way in sport and one way in touring. It was mostly freeway driving, but there was a 10 mile section of 4-lane 55 mph road with stop lights. While at cruising speeds, I noticed no difference in the action of the instantaneous MPG. As for the average, there wasn't a statistically significant difference there either after the trip. My car is also a manual and I don't have MRC, so the only thing sport mode can do it tighten the steering (which I can't feel if it really does) and maybe adjust throttle response (clearly it doesn't change the shift points).

In sport mode when cruising above 45 or so, I'd have to imagine the car would be in 6th. That is, I don't think the car would sit in 4th or 5th gear just to keep the revs up. With that in mind, I can't imagine how it would impact fuel economy. When encountering several lights during a drive, even if sport mode does not effect throttle response, I would imagine it holds gears longer, which would be less efficient. I would guess it is entirely dependent on driving atmosphere, and the more frequently you have to accelerate from a red light, the more dramatic the impact will be on your gas mileage. However, I would guess that the difference is likely imperceptible.

Even more important than the driving atmosphere would be your individual driving habits. Assuming you drive the car the same way in touring and sport, I would be shocked if there were a noticeable difference. But, this is all speculation.

flycaster
04-24-13, 09:36 PM
I find your report, gfxbt, amazing. I was just fooling around with my Z4 (AT). Drove it one way on sport and the other way on drive, while checking the mpg (started from 0). You know what? No difference, the same unexpected results on the same day from two different cars. Very interesting...

bravnik
04-25-13, 12:00 PM
In city driving you would probably notice a small decline due to the fact that sport mode holds the gears a little longer but really it should be marginal.

I thought the steering got firmer the harder you drive the car. At least that is how I feel it. Just normal driving in Sport Mode the steering firms up a bit but under hard cornering it gets really nice and firm and MRC firms up more and more as well.

wongluk
04-28-13, 10:50 PM
sounds like the sport mode (unless you have Magnetic ride) only changes the shift map and throttle map BUT not performance...ie: changes shift points and how sharp the throttle response is...if you have reached a steady speed on highway, I dont see how sport mode changes your mpg

blue_skies
04-30-13, 01:56 PM
sounds like the sport mode (unless you have Magnetic ride) only changes the shift map and throttle map BUT not performance...ie: changes shift points and how sharp the throttle response is...if you have reached a steady speed on highway, I dont see how sport mode changes your mpg

Indeed, Sports mode holds lower gears longer, unless you drive with a heavy foot, upon which Touring mode then also becomes a lot more responsive.

It is hard to compare Sports against Touring modes without taking into account the PAL algorithm.

Once the car is at cruising speed, the selected mode makes no difference, as the car is in the tallest gear.

I have seen 'best' freeway mileage hovering around 28/29mpg, and the 'worst' city mileage (lots of stops and acceleration) hovering around 18/19mpg. (In a 3.6L automatic).

Driving in Touring mode with a heavy foot is likely to be worse than driving in Sports mode with a light foot - because of PAL overriding the shift points.

As for me - I typically end up around 20/21mpg in 'commute pattern' driving - a bit of freeway, expressways, lots of stop and go, traffic lights.

It doesn't change all that much for me in the end, I have tried both modes and light and heavy foot control.

I don't have the MRC, so I drive in Sports mode almost exclusively with a heavy foot. I keep seeing 20/21mpg in City and 28/29 on Freeway.

Regular gas, 87 octane.