I stand corrected, & a bit of websearching has confirmed things.
However, even if you used the efficiency of the record holding marine engines for a car, then you still lose half of your fuel as heat.
Clearly variable speed driving & short periods of use make car engines very much less efficient than laboratory figures might say, so losing between two thirds to three quarters of your fuel to heat is a real possibility for many motorists.
The 50% plus figure for marine diesels is partly because they are usually run at constant rpm for long periods. Cars are not as efficient, but can still manage over 40%, although it does depend on the weight of your right foot 
We also have in the real world the rear trim panels which are never optimised and act like a drag increasing parachute so bench mounted efficiency would never compare.
Nature at it again,
Some good news?
I love the idea/principal.
I do wonder why, if they were tested with “great success” nearly 10 years ago why they are still 5 to 10 years away for a commercial offering? I hope we’re not into Nuclear fusion territory here…
Yes indeed but even baby steps are moving towards a better cleaner future.
A step (up) here
I fully advocate carless cities with free, clean, safe, efficient public transport. I hope Montpellier is and that other cities in France will follow.
Also, more buskers permits!
Another example of where humankind’s fiddling isn’t helping.
Also a thing to keep an eye on.
Lots of hopeful info here.
Pertinent quote in this article…
I would agree, some think its others resposibilty to reduce, it couldnt possibly them causing the issue.
Good info here.
Oh FFS! This is just a very expensive sticking plaster.
We must #stopburningstuff
Drax are scum, they are just virtue signalling whilst destroying forests.
I only know the name Drax as a baddie in the Bond films.
Not far off the truth. There were several investigations but these are big powerful people who can buy silence and committees.
Depressing reading, & zero surprise.
Yes depressing, have you seen this?