B8 AUDI A4 CR TDI.....Economy

[Diesel Donkey]

Hi,

Diesel Donkey here in wet Scotland......with a new motor.......3 year old B8 A4...143PS
My previous motor was a 2001 B6 A4 with a AWX 1.9 PD......130PS.

I am looking to see if anyone has experience of the new CR TDI compared to the PD unit.

The 2001 A4 had clocked up 228000 miles before being written off due to a bad driver doing a U turn in front of me.....I had rebuilt the turbo cleaned out all the carbon and replaced the bushes and rings etc....also cleaning out the inlet manifold and EGR....for the third time.....messy but necessary. The car went like a rocket and used no oil........that being replaced every 10k.

The car would easily do 750 to 800 miles on a tank with average MPG of 62+ (Imperial Gallon). My replacement 2008 B8 is averaging 44MPG......for a car that produces less CO emmissions why should it consume far more fuel than the old PD engine.

Does anyone have similar experiences in comparison with these engines? Is this called progress? The B8 is a good car but could be great if it was fuel efficient.

I was looking at the plug in remap ECU boxes but they all say the same thing but prices vary so much.
I would like to remap myself however unsure of the best software to use any ideas on this.

I am a Mechanical Engineer so my understanding is fairly good on the modern day engines........

DD

[geeforty]

I have an Exeo which has the same CAGA engine as your B8 A4. Economy has been poor compared to a previous VW TDi's with AHU (90BHP) and AJM (115 PD) engines where 50+ mpg was possible without even trying, this Exeo has averaged 42 MPG, on a long run I managed to get 46MPG (whoopeee)
Just had it serviced yesterday, and made a point about the economy, and they checked everything. It now has Castrol oil in it, and on the trip back from the dealer just scraped 50MPG after a 35 mile run.
They said that the MPG might improve with fresh oil, whether they reset anything else I don't know, but when I checked the DPF with VCDS before they had the car it was 16% soot loading (so should be OK) and the oil quality / ash levels very low (its on QG1 service - long life, but has actually been serviced at 10K mile intervals - the next requested service was not actually due for another 8000 miles)

Apparently low 40's is the norm for these 2.0 CR engines, power delivery is much weaker than the old 115 / 130 PD engines. Basically my opinion (which was echoed by the technician at the SEAT garage) is that the emissions were the driving force on this design, with economy being sacrificed, the PD 130 unit is sort of the pinnacle of performance / economy / efficiency of emissions. A friend went from a 2003 BMW 320D and has the same results - old car 50+ MPG no probs, new A4 - 42 if your lucky.
Nigel.

[TwinCamMan]

At the start of 2009 I bought the new Skoda Superb CR170 2.0 TDi and to date it's returning 55-60mpg. I've covered 75,000kms which is just under 50,000 miles. And on a long run on the motorway it will exceed 60mpg with the cruise control set at the speed limit. I know the standard 1.9 PD version (105 bhp) can't match this as I tried it before I bought the CR170, plus the 65bhp difference and improvement in torque is something I couldn't live without. Had a 2005, A4 before the Superb, which had the 2.0 TDi PD (140), with the dreaded BLB engine and did 60,000 miles in it. Got 50mpg all day long in that but not a whole lot more. The CR is quicker, more responsive and more economical and the only issue I've had with it is with the DPF not regenerating, that will be removed this year!

[geeforty]

On the SeatCupra forum, and ones I have seem advertised for sale with the 168 engine, they do seem to get much better economy, even with the lower gearing, but if you look here

http://www.spritmonitor.de/en/overvi...ml?powerunit=2

The 143 engine gets average 7.6 and 6l/100KM = 37 - 47mpg

I also notice an improvement if you use shell V-Power, but not sure if the improved MPG out weighs the extra cost.

Yet for the Skoda 170 engine
http://www.spritmonitor.de/en/overvi...80&powerunit=3

it seems high 50's is the norm.

Perhaps there is something strange with the CAGA and CAHA engines in the longitunidal installations

[geeforty]

Also just had a quick look the CEGA engine in the Skoda (170CR) is internally somewhat different to that of the CR engines in the Seat and Audi (CAGA CAHA) from what I can see in terms of crankshaft and oilpump.
The Seat and Audi have the oil pump / gear driven balancer shaft arrangement, where as the CEGA engine has a normal oil pump with no balancer shaft, like the earlier PD units. The Pistons and Heads seem similar.

The CR engine in the Seat and Audi is very smooth and progressive, it doesn't have the 'hard' power delivery of the PD units, maybe a remap could sort these things, but until the warranty expires I think I will have to leave it alone.

*** Update - the CEGA engine is in the Octavia, the CBBB engine is in the Superb - sorry misread the post - this has the balancer shaft arrangement same as the CAHA CAGA,
and the fuel figures are
http://www.spritmonitor.de/en/overvi...78&powerunit=3

similar to the Audi and Seat