Indeed. I was being generous. In normal operation 20% thermal efficiency would be reasonable. The power stations supplying the Tesla Roadster, on the other hand, will be running at maximum efficiency just about all the time. Their electric motor won't be running at maximum efficiency either, of course.
Ian
Didn't find your answer? Ask the community — no account required.
I
Ian
They say something about costs based on your power companies incentive plan. I presume that' the equivalent of Economy 7.
I prefer "realist", thank you very much.
Ian
D
Dave Plowman (News)
Funnily on the same journey as I took the Prius on it returns almost exactly the same MPG. But with a lot less effort. And a 20 year old 3 speed auto is hardly at the cutting edge of economy. My BMW with a 5 speed auto beat the Prius on the same journey by about 20%. A modern diesel auto with far more performance would near double that MPG.
The Prius scores by having regenerative braking and not using any energy when stopped. Those go straight out the window on a reasonably clear motorway journey where it's running at near maximum power. Where it simply isn't as efficient as a conventional engine/transmission.
D
Dave Plowman (News)
Autocar take every car they test over the same route, as part of the test. A mixture of suburban roads - 30, 40, and 50 limits. Some 30 miles. Designed to be fairly representative of the roads most people actually drive on. They give this result separately from the *overall* test result
- which of course includes maximum speed runs etc, so will be lower than most get. And the Prius was well below average in this test given its size price and performance.
C
Clive George
That's given it a test of how the journalists drive it. I wasn't talking about them. I'd guess that Prius owners (the "people" I referred to) drive it differently to them if they're getting rather better mileage.
This isnt break-through though is it, its lower than you get from many modern cars - the missus gets 46 daily on local hops, 50-52 on a run, from a normal petrol 1.6 with plenty of oomph and no special driving, no gauge watching. My brother gets 40-42 from his 3 litre turbo D bimmer, while booting it regularly. Martin Sylvester is the only person I've heard of who has gotten what I consider a good result from a hybrid.
A
Adrian
Dave Plowman (News) ( snipped-for-privacy@davenoise.co.uk) gurgled happily, sounding much like they were saying :
Not really surprising, since it's a zero-sum game. The energy going in (petrol) MUST equal the energy coming out (heat plus kinetic).
The only way in which the Pious can do better is where the technology can overcome the inherent inefficiencies in a normal petrol car - very slow moving urban traffic.
And if you're in very slow moving urban traffic that much, it usually makes more sense to park and take public transport.
Mind you, it's nothing new at all - we were at Amberley Museum on Saturday, looking at the 1920s petrol-electric hybrid buses.
D
Dave Plowman (News)
I take it you can't understand the idea of suburban roads and a route designed to give a true comparative test - rather than official figures which the Prius was designed to shine in? And on that route there's little chance of hammering any vehicle.
They all seem to drive with the object of getting the very best figures. And love quoting those. Whether they are accurate or not I can only speculate. But of course if you drive any car gently you'll get good MPG. Spectacularly so with many modern vehicles.
C
Clive George
No, I understand entirely. It's a comparative test for the type of driving the journalist does.
I think they probably are getting the figures they say they are. And yes, it's probably through driving gently. I never claimed otherwise - I never claimed the car was inherently economical, my point was about the results that people are getting - they probably aren't fibbing.
cheers, clive
D
Dave Plowman (News)
Driving round the high streets of Teddington and environs? I'd have thought that rather out of the way for most journalists - unless they work for Haymarket.
I'd say the problem with most car tests is they head for somewhere 'interesting' - the Welsh mountains etc. And then drive the car hard. The whole idea of the above test is to be closer to how most use a car. To give a more balanced view after they've hammered it around. But I don't expect you to understand this since you don't read Autocar. Or probably any other motoring mag.
C
Clive George
Eh? Where did that one come from?
Here's the problem : The autocar test gives different results to what many owners report. So, how to explain this? Owners lying/mistaken? (your option) Or test not actually matching what those owners do? (mine)
I've got no great axe to grind about the prius - eg I wouldn't bother with one, and TBH a diesel with the same care would probably be rather better. But there has to be some explanation why people report differently to the magazine, and I don't think it's because they're lying/mistaken.
cheers, clive
Join the Discussion
Have something to add? Share your thoughts — no account required.
Didn't find your answer?
Ask the community — no account required
Report Content
You are reporting this content to the moderators. They will look at it
ASAP.