How realistic are the small petrol engines though? I mean, I always thought it was a great idea and solved a lot of issues but the VAG ones and the Fiat Twin Air seem to be rather difficult to get good economy from.

Incidentally, Toyota went from 1.5l to 1.8l in the MkIII Prius to improve fuel economy. They also send the coolant through a matrix in the exhaust to warm it up more quickly.

I hope you are implementing some of the ideas I’ve had for fuel economy 🙂

The anecdotal evidence is that my fiance’s 1.4 TDI Polo is much more economical that her 1.2 16V clio on a 14mile stop-start commute. The journey is quite hilly so I think the extra torque is a big factor. (I wish the Polo had a 6 speed box for extra motorway legginess.)

I’m not sure this type of commute is good for any sort of engine really.

1.4 diesel Polo bluemotion here – 50 mile round commute everyday. 65 MPG on A roads, 55 MPG on rural roads and 35 – 40 MPG in the short 2 mile stretch of stop, start traffic. Generally get between 55 – 60 MPG average over the journey depending on traffic.

You obviously want to save money, which you won’t do by buying a different new car.
You need a bag o’ shite old one, that is light, reliable and easy to drive in traffic.
You need a MkII Nissan Micra, 1.3, wait for it, CVT auto.

Sorry.

Diesels are generally pants for short journeys or heavy traffic. Can’t believe that anyone would argue to the contrary, no matter what the efficiency says. Continual use at low loads on a Diesel engine is a good way to incur very hefty service bills that are simply not an issue with petrol cars.

The anecdotal evidence is that my fiance’s 1.4 TDI Polo is much more economical that her 1.2 16V clio on a 14mile stop-start commute.

15 miles is quite a long time in heavy traffic, so the warmup factor is less of an issue.

I wouldn’t say that diesels are particularly bad in heavy traffic as long as they are warm.

ONLY heavy slow traffic and no higher speed driving is a bad idea though, due to coking issues.

Incidentally, this morning’s commute was 11 miles, involving a couple of traffic lights, some 70/50mph dual carriageway and the M3. It took about 8 miles and 12 minutes before the coolant got to the normal 90 degrees ie most of the journey.