DSG coasting

[Beefy McMoo]

I remember seeing somewhere that most modern engines use NO fuel when you are coasting in gear.  I.e going down hill in 6th gear but with foot off the loud pedal.  Where as if you knock the car into neutral going down hill the engine has to use fuel to avoid stalling.  Please feel free to ridicule me if I'm wrong. 

[08micsta]

Actually it sounds like a good theory 

[Beefy McMoo]

Am I right TT am I, am I? 

[AlanD]

I remember seeing somewhere that most modern engines use NO fuel when you are coasting in gear.  I.e going down hill in 6th gear but with foot off the loud pedal.  Where as if you knock the car into neutral going down hill the engine has to use fuel to avoid stalling.  Please feel free to ridicule me if I'm wrong. 

No, you are correct (sort of). The engine map will see that you do not have your foot on the pedal when in gear and use a very minimal ammount of fuel, to say it uses NO fuel is just plain silly lol (engine would cut out . . . . ). Where as if you leave it in N it will use x ammount of fuel to keep the revs at tick over.

[Beefy McMoo]

I remember seeing somewhere that most modern engines use NO fuel when you are coasting in gear.  I.e going down hill in 6th gear but with foot off the loud pedal.  Where as if you knock the car into neutral going down hill the engine has to use fuel to avoid stalling.  Please feel free to ridicule me if I'm wrong. 

No, you are correct (sort of). The engine map will see that you do not have your foot on the pedal when in gear and use a very minimal ammount of fuel, to say it uses NO fuel is just plain silly lol (engine would cut out . . . . ). Where as if you leave it in N it will use x ammount of fuel to keep the revs at tick over.

Why would the engine cut out??  as you are in gear and the wheels are turning the engine you don't need fuel to keep it going?  Again probably wrong, but thats what I believed.

[Teutonic_Tamer]

yea!!^^^ shouldnt be doing that

Cheers!  I assume the others with DSG slip it into N when at a temporary standstill?

It depends.  If I'm in a queue, inching forward, then stopping and so on, I just leave in D (or tip mode).  However, if I'm at red traffic lights, it is handbrake on and straight into neutral.

It's a bit of a pain that the car creeps forwards when in D/S/tiptronic and it didn't take me long to get sick of holding the foot brake on at lights.  Besides I think I read something in the manual about not holding her on the foot brake for long periods of time while at a standstill and in gear.

Yeah - but the creep is the same for conventional autos too.  But on conventional autos, they have a fluid flywheel/clutch, and could sit all day long in gear with the foot on the brake (providing the oil cooler is up to scratch).

Agreed, not good to keep your foot on the footbrake.  OK, its not particularly bad for low speed stop start around town stuff, but if you have just had a high speed stop for some red lights or sommat, then keeping the foot on the brake pedal can warp the brake discs, due to "heat-soak" from the pads.

edit: Excuse the questions but I have only ever owned cars with manual boxes before the GTI

We all gotta learn new things sometimes in our lives!   

[Teutonic_Tamer]

When you are holding it on the brake you are not damaging the clutch.

Wrong.  When the car is stationary, in gear (with the engine running), and the foot is on the brake - the clutch is being held on the "bite-point".  With the DSG having a wet clutch (running in oil), it is designed to cope with this for very small periods of time.  However, holding a stationary DSG in gear with the footbrake is exactly the same as holding a manual car, say on a hill without the handbrake, and just relying on slipping the clutch - not good!  (And a driving test failure, and also a very short clutch life).

[Teutonic_Tamer]

Is it OK to do it in the manuals then? 

Do what in manuals - coasting, or holding a stationary car with the footbrake?

If it is the first, then absolutely not.  And I've no doubt it would be illegal too - you could be prosecuted for sommat like "failure to be in proper control of a motor vehicle".  Don't know exactly what part of the Road Traffic Act it comes under, but I'd guess at 6 points and a £2,500 fine!

If it was the latter, then see my reply of two posts earlier.

[Teutonic_Tamer]

Is it OK to do it in the manuals then? 

Should be fine in a manual, over small distances, as there's oil pump to drive.

Huh - manual gearboxes don't have oil pumps in them, only DSGs, conventional autos, and CVTs!

[joesgti]

Micsta i find that offensive it took me 1 hour with all my photo bucket skills to do that. 
Just to let you know how good my computer skills are here is a new one i did for Mr greenouse. But for some reason when i offered it to him he respectively declined. 


 

i really really lol'd