Petrol more economical than diesel - Official.

The message from Johannes contains these words:

However, not all cars are Citroen C1s.

That title should read "One particular test for one particular car shows that under certain circumstances petrol delivers more mpg than diesel"

A diesel engine is always more thermodynamically *efficient* than a petrol, it's how you apply the delivered energy that determines the mpg figures....

In convoy? Which one was leading? It makes a difference.

Petrol cars in general are quicker and more refined. But few petrol models are more economical than the equivalent diesel. Especially with bigger cars.

My Rover 218 (old I know) returns an average 45 mpg (and it works hard for that). None of the petrol models come close.

That's terrible. Although the 1.0 is a triple, which improves efficience and reduces weight (diesel car is about 8% heavier) , which is reflected in the urban cycle figures for them (51.4 petrol, 53.3 diesel).

Extra urban of 68.9 / 83.1 tells the real story though - the HD is more efficient at steady speeds. I find the figures quoted by yourself hard to believe though.

Can't believe how slow these cars are: neither crack 100 mph, petrol 0-62 is

13.7, diesel 15.6. No matter how economical they can be, they're crap. I bet I could get the petrol to 30 mpg, and the diesel no worse than 35...

Johannes ( snipped-for-privacy@spam-not-sizefitter.com) gurgled happily, sounding much like they were saying :

When I saw the first C1 in the country, at Cit UK's headquarters, the senior bod I was talking to said they really weren't expecting to sell many diseasels, because the petrol was just as economical and generally better.

Bear in mind that the Aygo and 107 are the identical car. I *think* Cit are the only ones planning on bringing the diseasel in, though. They're certainly the only one with it in the price list at the mo. All three have the same petrol lump.

Which one was leading and how far apart are they. as the first would give a not inconsiderable slipstream to the second.

Tom..

In news: snipped-for-privacy@4ax.com, Chris Bolus decided to enlighten our sheltered souls with a rant as follows

My even older 3.5 V8 (not diesel) Range Rover automatic probably averages about the same as your Rover - cost wise, and I don't have to listen to the sound of Dr Diesels Evil Invention.

I think it's exempt from the congestion charge in London as well, which would be a bonus if I ever went to the hell hole.

Eh? How do you work that out? Unless you're on LPG?

FWIW the Rover is cheap, battered, but reliable & economical and big enough to hold son's ice hockey kit (small hatchback? forget it!). But it's only doing the job until the LPG Omega engine rebuild is completed.

Congestion charge is only exempt if your car is on the powershift register & you obtained a grant when converting your car (or buying if brand new dual fuel).

Personally I'm more impressed by good fuel economy that good acceleration or top speed.

What's the powershift register? Is that something whereby you register for con-charge exemption if you've got an LPG car?

And WTF has having been given a grant when converting got to do with con-charge exemption?

Peter

IIRC, it'd also be exempt if it was a bus. LWB Land Rovers with 8 seats count, so if Pete removed the back seats and fitted a few rows of wooden benches, he'd be in with a chance.

True, but then it wouldn't have caught your eye :-)

True, hence we have heavy goods vehicles, busses and trains with diesel engines. However, the 1.0i engine must be a very clever design.

You're right that these are the official figures. The Sunday Times testers were equally surprised over the low petrol consumption i the test. They spent long time dripping petrol back in the tank to ensure that it was truly full up after the run.

Of course they're no sports cars. But as long as they can cruise comfortably at 70mph, that's all you need. Commuting to work only needs the space for on person plus briefcase.

Similar power petrol and diesels are often similar in consumption at highish speeds. Nothing new there. Now if they'd driven across London for a similar distance the results would have been very different.

I wonder if the heater / AC was set different on the two cars...

Cruising comfortably at 70 is not the whole story, is it...

It ceases to be exempt if it or it's converter is removed from the register. An absolute con.

So they are about on par for performance with all sub 1000cc BL Minis (except rare and early Cooper), Morris 1100, Pug 104, Datsun Cherry

100A, pre 16v Micra, Renault 5 and a whole host of other small cars, all of which were quite adequate. Next door but one only swapped her Mini for a Pug 106 this year. If you are buying a small economical car you want a small economical car. Heck I can remember the Shell advert that claimed an amazing 44mpg for a Mini running on Shell, 80+mpg for a M25 cruise shows how far vehicles have developed in the last 25-30 years.

It might be the whole story if the purpose is A to B. Personally, I prefer a bigger car for stability, comfort and quietness. My Saab 9000 CSE 2.0 LPT is just the job for me, but that's another story.