Fuel consumption observation and musing

Not a scientifically disciplined observation, but since I stopped drinking caffeinated coffee, my car averages 1-2 mpg more in around-town driving.
When I was ordering the car, the salesman said using the Sport button doesn't change the mpg much. I think it's at least partly due to when it's active, the subjective sense of increased throttle response causes a driver to not stomp the pedal as much to be gratified, even as subtle as the effect is.



Edited 1 time(s). Last edit at 09/01/2014 10:18AM by Laz. (view changes)

Edited 1 time(s). Last edit at 09/01/2014 07:44PM by Laz. (view changes)

I figure the extra money I spend on gas, I save on coffee.

Haven't really checked out the difference in gas mileage between using and not using Sport mode. My guess is, when cruising at a constant speed, it makes no difference. It's the more instant throttle response that would have one put ones foot into it with more enthusiasm that would cause most of any drop in gas mileage. So far, I've mainly used it when getting into some fun twisties, specially ones with elevation changes.

Have to also admit that when using Sport mode, it enhances the burbling/popping even more because I have the PSE. It's like enjoying an afternoon listening to Tchaikovsky's 1812 Overture with its grand finale. Combine that with the fun in the twisties and you have permagrin etched into your face for quite some time afterwards.

[www.youtube.com]

is the finale to the PBS production on the Capital grounds on the fourth off July. Played by the National Symphony Orchestra. The cannons firing as the fireworks start.

(The secret was to go down the night before for a full dress rehearsal. Full production without the hundreds of thousands the fireworks brought. But then someone publicized it and you could no longer park up by the Supreme Court and stroll in for ringside seats. The rehearsal became as crowded as the real thing.)

Now imagine a perfect night as you drive your Boxster top down and park among all those historic buildings. Just you and your girl and a blanket to spread out on the lawn and maybe a picnic.

My 987 gains about 10% more horsepower and picks up another 2-3 mpg, right after it's washed. Engine runs smoother too.

Porsches aren't inanimate. Pass it on.

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Roger987
My 987 gains about 10% more horsepower and picks up another 2-3 mpg, right after it's washed. Engine runs smoother too.

Porsches aren't inanimate. Pass it on.

Actually, it only SEEMS like 10% more horsepower. It's actually, the more aerodynamic nature of the freshly washed and waxed, smooth, slippery surface of the Boxster's svelt curves that allows for that extra pick up and extra gas mileage. Why, even around town, you save enough for a Café Grande at Starbucks.

the Sport activation tends to allow for one higher gear, thereby possibly actually reducing fuel consumption. Concerning the caffeinated effect, in my case I was more impulsive with the gas pedal, with its concomitant increased fuel consumption. Yes, these are my behaviors. Your results may differ.

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Laz
the Sport activation tends to allow for one higher gear, thereby possibly actually reducing fuel consumption. Concerning the caffeinated effect, in my case I was more impulsive with the gas pedal, with its concomitant increased fuel consumption. Yes, these are my behaviors. Your results may differ.

Do you make use of the up-shift indicator when you have it in Sport mode?

I tried to use it a few times and felt I was really lugging the engine.

Around town, I would think Sport mode would use more fuel with its higher idle speed. Specially of you hit a lot of red lights

it's something of a killjoy and yes, it gets the engine at least close to lugging. Going up any sort of hill at 40 in 6th makes the 3.4 engine sound close to unhappy, torquey as it is. Maybe by strictly following it, one could get "city" mileage up to the EPA figure. What city it refers to is beyond me. Maybe Oklahoma City! Very unrealistic for reasonable driving.

I had to go out for something, so after reading your post, I specifically watched for the up-shift light and on mine it works in both normal AND Sport mode. I still find it probably the most useless feature on the 981.

I find the current/immediate fuel consumption readout on the BMW to be far more useful for this sort of thing. Like the example you gave - driving at 40 MPH in 6th on the slightest incline will actually show higher fuel consumption (less mpg) than if you have it 5th or even 4th gear. Probably the best experience with that sort of thing is riding a multi speed bike. Having it in too tall a gear increases the effort to peddle considerably. I would think the increased effort required, would translate into higher fuel consumption when it comes to a car..

Maybe the US cars have a different Sport activation set-up, perhaps to do with our EPA. We agree: it's pretty much useless because of its unrealistic shift points.
The fuel consumption per active/inactive Sport throttle setting might be dependent on a matrix of parameters such as exact gas pedal angle, how fast and how far it is pushed/released, the gear and the relative "delta" of the terrain being traversed. Essentially, as my sales guy said, use of the Sport throttle makes very little difference in consumption. I've previously wondered how much using it, say, uphill in 6th would make me think the engine isn't lugging as much because it's not me pushing the pedal down more to maintain speed or accelerate.



Edited 1 time(s). Last edit at 09/02/2014 04:16PM by Laz. (view changes)