Drive Select
- Thread starter JT-007
- Start date
Efficiency can disengage the clutches on DSG enabling you to coast/freewheel down hills, and also control the air conditioning compressor to disengage if free cooling is available.
Really? Isn't that coasting in neutral? That's considered bad practice as you are not fully in control of the car and can't rely on engine braking to assist the brakes - disengaging the clutch in any gear Without changing up or down on a driving test is an instant fail. Can't see a manufacturer introducing a system that ignores that fact. Any auto transmission that slips the clutch or disengages the clutch at speed for longer than a change up/down would be considered operating under dangerous fault by the DVSA.
More likely the ECU senses the gradient is assisting from the amount of fuel injected / engine speed / wheel speed and adjusts the throttle response to reduce injection - coasting in gear by minimising the fuel delivery irrespective of throttle position. Making your right foot lighter on the downhill if you like. And legal too.
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I would have also thought that coasting downhill would use more fuel as the engine has to tick over at idle rather than use its momentum to keep running and thus no fuel
Yes, really, coasting, fully disengaged clutches.
Suggest you write to Audi and VOSA to express your indignation.
Sigh.
Re fuel usage, you are correct, in an overrun situation, it is possible, to use zero fuel during engine braking, however in some/many situations, the distance covered by coasting and only idle amounts of fuel going in, far outweighs the short period of zero fuel in an overrun situation, based on the trade off of covering a long stretch with minimal fuel and no engine braking, vs. a shorter distance with zero fuel and engine braking.
I know it's alien to put a S3 into Eco mode (I only managed 20 mins), but if you try it it may give you some idea!
Autocar article:
Sometimes it is preferable to coast through life | Autocar
Suggest you write to Audi and VOSA to express your indignation.
Sigh.
Re fuel usage, you are correct, in an overrun situation, it is possible, to use zero fuel during engine braking, however in some/many situations, the distance covered by coasting and only idle amounts of fuel going in, far outweighs the short period of zero fuel in an overrun situation, based on the trade off of covering a long stretch with minimal fuel and no engine braking, vs. a shorter distance with zero fuel and engine braking.
I know it's alien to put a S3 into Eco mode (I only managed 20 mins), but if you try it it may give you some idea!
Autocar article:
Sometimes it is preferable to coast through life | Autocar
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More coasting in a 8P:
The future of Stop Start and Freewheeling
Coasting feature from 3'00"
The future of Stop Start and Freewheeling
Coasting feature from 3'00"
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oufc1976
Registered User
I've a manual 2.0TDi and I'm still struggling to see the point of any of the modes other than Dynamic.
Given that gear changes are down to me, Efficiency is only efficient if I drive it...efficiently.
In fact, I spent the first 2k miles in Efficiency mode Mon-Fri, averaging 50mpg if I drove it like a nun. Then last week decided not to bother, stuck it in Dynamic and left it there since.
I now drive it swiftly and average....50mpg.
I can only put it down to having to make the car work a little harder in Efficiency to get it off the line, whereas in Dynamic there is always power waiting for you.
Is there a link anywhere that fully explains the differences, specifically for the manual box?
Given that gear changes are down to me, Efficiency is only efficient if I drive it...efficiently.
In fact, I spent the first 2k miles in Efficiency mode Mon-Fri, averaging 50mpg if I drove it like a nun. Then last week decided not to bother, stuck it in Dynamic and left it there since.
I now drive it swiftly and average....50mpg.
I can only put it down to having to make the car work a little harder in Efficiency to get it off the line, whereas in Dynamic there is always power waiting for you.
Is there a link anywhere that fully explains the differences, specifically for the manual box?
I have to admit that so far I've found dynamic a bit frustrating.
30mph = the car drives around in 3rd - 4th gear at 3000+ RPM
60mph = car drives around in 5th.
Manually change up as I'm either going down hill or cruising & a couple of seconds later it overrides me & changes down again.
It's like there's some setting where the revs are not allowed to drop below 3000RPM...
30mph = the car drives around in 3rd - 4th gear at 3000+ RPM
60mph = car drives around in 5th.
Manually change up as I'm either going down hill or cruising & a couple of seconds later it overrides me & changes down again.
It's like there's some setting where the revs are not allowed to drop below 3000RPM...
I'm pretty sure when you're on efficiency mode and the clutch has been disengaged, as soon as you touch the brake or the accelerator the engine will increase the revs back to normal so you have full engine braking.
Yes. I ruled out Dynamic until I thought of that (Dynamic defaults to S mode in the gearbox).
