Well, for the first time in a long time my car told me this morning I got almost 75mpg on my way to work!

:confused:

OK - It was quieter than average on my commute and much of the journey was at low speed and low rpm, but I wondered if what I tweaked over Xmas has really had the side effect of better economy.

Basically I've fitted a lightweight flywheel (so does the engine use less fuel spinning up a light SMF compared to the stock DMF) and also removed the AC, so I have a shorter 6PK auxilliary belt, just between crank and alternator.... Does the fact the aux belt usually also wrap around the AC pump perhaps imply more "effort" by the engine to drive it?? There is also the weight issue - probably saved around 10kg with the flywheel, and have knocked around 8 to 10kg off the front of the car removing the AC pump, condensor, and pipework.

Oh, the car said I also got 65mpg on my way home, but it was a bit busier, especially on the outskirts of Exeter.

I would imagine it's the AC pump removal thats done it. I'm sure Ross said the pump works at 10% duty to keep the refrigerant moving even when the aircon is switched off. All that said, they are some mighty impresive numbers

i wish i could get above 55mpg , mine is rubbish at the moment, even after the removal of the Dragon box

It's very rare that I even see 50mpg out of mine.

40-45 is the norm.

The flywheel will spin up easier yes, but the heavier a flywheel is the more kinetic energy it has and the more efficient it will be when kept up at speed. What we give with one hand we'll most likley take with the other

Pretty amazing - will you do mine please? 55-ish when pootling, 20's when enthusiastic.

What we give with one hand we'll most likley take with the other

You ever thought of another vocation ?

Like preaching

75mpg - you must be living on DevonUtopia

You ever thought of another vocation ?

Like preaching :

Hmm Reverend Big W Its got a ring, or should that be a peel

Hmm Reverend Big W Its got a ring, or should that be a peel

So astute of you :P

So astute of you :P

Careful, next one may be an Ambush, very Artful though

Careful, next one may be an Ambush, very Artful though

Technically the weight saving is correct - but you remember that post that I put up - for acceleration purposes lightening the flywheel as you have is like dropping 150 pounds of weight off the car!

Also I wonder how much energy a slightly slipping clutch loses as heat....

Glad to hear you're happy matey

Bas

As Basil has said I reckon the biggest factor will have been the flywheel (although the aircon will also have made a difference). In Uni last year, I was tought that due to inertia if you were to take for example 10kg out of a car's recipricating component e.g. flywheel - it would have the same effect as taking 30kg out of a stationary component, like stripping a seat out for example.

Out of interest, I have been planning on getting a SMF and uprated clutch at some point - and is the SMF lighter that the DMF then?? If so, how much do you reckon by???

Cheers,

Dave

With the lighter flywheel, is your idle rougher than before?

not only the most powerful fabia but also now the most economical one, keep up the good work

Is the PD100 TDI Fabia/Ibiza Ref Sport/Polo Sport better than the vRS?

Is the PD100 TDI Fabia/Ibiza Ref Sport/Polo Sport better than the vRS?

And the award for the most random post of 2008 goes to welshy for this post :confused:

Is the PD100 TDI Fabia/Ibiza Ref Sport/Polo Sport better than the vRS?

Overall (as standard), in economy terms it probably is due to lower power, yet narrow wheels to keep rolling resistance down.

Overall (as standard), in economy terms it probably is due to lower power, yet narrow wheels to keep rolling resistance down.

As well as weighing a fair bit less too (down to not having a 6-speed gearbox, big heavy brakes and wheels I guess)

Chris

Also don't forget the drop in weight of the driver's right foot -

what with all the new bits running in there.....