LG John

So there I am washing the dishs and thinking about recent test drives/comparisons, etc and it occured to me that Neil's cup computer thingy reported 31mpg during his fairly hard driving session last night. It was then that I remembered this thread:

http://www.scoobynet.co.uk/bbs/threa...hreadid=220242

You'll note from the first page that the mpg in the V-dub PD150 during my drive was 30+ and if I recall it was 32mpg. That drive was a few days ago on pretty much the same route, for the same length of time and under very similar conditions (i.e. some hard accleration and some cruising) to last nights run with Neil.

It was then the penny dropped:

moddern PD diesel = 32mpg
moddern 2.0 petrol = 31mpg

WTF

I can only attribute this to the Clio being lighter and the PD having a fuel greedy turbo that guzzles when used.

Just goes to show though, perhaps these so called super-diesels are gaining their extra grunt at the expense of their biggest trump card........interesting!

Frazer

Yeah I dont think the TDI's like it when ur totally caining them, as I said my cup wil get 38-41 mpg on a long motorway run. Where a TDI would see 48-53mpg (dad had a TDi) Kenny my dad got his Cupra R you want a wee look at it? I think it might change ur mind about another turbo car.

[Edited by Frazer - 6/19/2003 12:12:36 AM]

LG John

It won't - I get totally addicted to the turbo rush which is why my fuel economy has dropped to about 23mpg despite mainly motorway driving!!! I'd love to see your dads car.......and rob his alloys

Clearly the PD will get much better economy if driven with that in mind but its amazing that when driven in anger its no better than a petrol hot-hatch

TopBanana

Get over it dude

NACRO

If you want economy get a diesel Saxo- my mother in laws gets over 60mpg. If you want a decent fast car get a petrol powered one.
I can't understand the obsession with diesel- it costs more per ltr, couple that with the higher initial cost of purchase and you have to do a hell of a lot of miles to get your money back.
In Europe where diesel is half the price of SUL in some cases these cars make perfect sense, in the UK I don't think so(except to beat the tax man).

LG John

Well I must admit I'd always banged the diesel drum but I find myself questioning my own opinion here. I'd still recommend a 130PD over a 2.0 GTI to any non-enthusiast driver as they will get much better mpg, easier and punchier acceleration, etc but to anyone that likes a bit of right foot action the oil burners don't make so much sense when you factor in the cost of diesel, higher purchase costs, etc.

Of course if economy was really my motive I could buy a dual fuel astra like my dads. It costs him 15 bucks to fill up with gas and that lasts him 300 miles!!! Makes me sick when 15 bucks in the scooby will only take me round to the shops a few times

polarbearit

We used to have a VW Sharan TDI (I think it was a 110 ish bhp model) pool car, it used to return 17mpg! Now I know it was heavy and big, but even on a run it was only getting 27mpg

It was an auto which I don't think helped

SCOSaltire

110 isnt a PD model tho

its a mechanical type

brickboy

It's true -- cane a diesel and you get no economy benefits. But most of the time, you can't cane ANY car.

But's let's not kick off the whole diesel / petrol is-it-or-isn't-it-quick debate again

JLangg -- are you Upsoluted now? If so, how's it going?

TopBanana

Not yet mate, was due to happen this evening but that was cancelled. Some time in the next month or so I expect.

P.S. Getting my kicks this evening in a Caterham Superlight at Donny - getting excited now wahoo!!

mik

Since Diesels take a full lung of air every stroke and just inject differing amounts of fuel (not needing a stochiometric mix ratio) they have no throttle to disrupt the airstream, so are muchmore efficient at part throttle. Which is most of the time.

At full throttle the only advantage over a petrol is that diesel has a slightly higher calorific content.... minimal advantage.

So sometimes they are much better, other times only slightly

ianc

Have to say I'm very impressed with the 1.8T for economy...

On track, I can get it down to 12mpg

..but Mway cruising, had it over 39mpg!

(I don't know many other forced induction 4cyl 4wd's that can get that!)

Ian.

LG John

Good and clear explanation mik, cheers

mik

yer welcome

Paul_M

Plus the fact they run a much higher compression ratio (~20:1) than any petrol could which helps efficiency (more heat energy used in the expansion rather than lost as "useless" heat dissipated by the block etc).

But yeah most of the efficiency comes from running very lean 90% of the time.

JMP

I dont know about MPGs on that PD150, but however I drive with my PD130, I cant get it to consume a lot more then 6l/100km. Show me a 2.0l petrol get that driving around the town?

There seems to be a big difference in fuel consumption between PD130 and 150 according to VW Driver mag.

LG John

Bigger turbo = greedier perhaps?

brickboy

Golf PD130: 49.7 overall test mpg
Golf PD150: 42.7 overall

both from VW Driver