Reply to post: Re: Tce Engine

Renault Captur: Nobody who knows about cars will buy this


Re: Tce Engine

But on real congested motorways it's a very different story because the Prius comes into its own in slow traffic when it is on electric. A car with stop/start is stopping and starting the engine every time a few yards progress is made, causing a lot of wear. A Diesel or petrol car without is using fuel all the time to do nothing. Shortly after I got the Prius I was stuck in traffic on the M6, and in three quarters of an hour made barely a quarter mile of progress. Suddenly there was a strange noise, and I realised that the engine had only just come on to charge the battery.

If you can be sure of driving mostly on motorways at unsocial hours your Diesel may have an advantage, but my experience is that in mixed real world traffic conditions the Prius uses less fuel.

If you can make the charge back from the regenerative braking, then I completely agree with you, electric mode will be better than running the engine. However, if you are making the charge back by using the internal combustion engine as a generator (it is not designed to be an efficient generator, it's designed as a car engine), I suspect that the total power efficiency of motive force from engine generated electric charge sent to the wheels, vs total power efficiency of motive force from the ICE, are going to be comparable, if not slightly biased to driving directly from the ICE. Storage losses plus electric motor efficiency will need to be as good as, or better than, transmission losses for it to be better using the engine to charge the batteries than just drive the axle.

Does anyone know those comparative figures for hybrid vehicles? If driving the car from an engine-charged battery is still 10% more efficient than just using the engine then hybrids are a (literal) no-brainer for fuel economy, and ICE only cars should be phased out. If driving the car from the engine is even 1% more efficient than driving it from an engine-charged battery, then the design should really only allow for charging via regenerative braking (that literally is free energy, since you want to lose the kinetic energy anyway, you might as well get some use out of it).

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