Tow cars and trailers

Re your efficient V8 - is your engine one which shuts down a bank at
low load? I believe quite a few US V8s do that nowadays, so you were
actually getting 37mpg from a 2.7l I4 :-). Also I can't say I fancy
driving at 45mph everywhere - I measured my European petrol car at
39mpg last year after a 200 mile drive at 90mph.


Dan

Nothing that fancy. It runs on 8 all the time. My point that the roughly
round shape of a V8 has minimum surface area for heat leakage and has some
low tech but effective heat redistribution passages that increase
efficiency. Henry Ford figgured that out back in the 1930's.

The biggest problem with a V8 isn't the number of cylinders which have the
advantage of increasing the total piston area and decreasing pumping losses.
The real problem is internal friction from all those moving parts. A
somewhat plausable comparison is a 4 cylinder Lycoming 360 Cu In airplane
engine which can be easilly turned over by hand - something that is
impossible with my 318 Cu In V8. There are low friction thin films that can
be vapor deposited onto engine parts. Motorcycle racers use them to get 8 -
10% more efficiency. I'd like to see what that would do for the venerable
V8.

Combining our two ideas it seems that what you get with a more fuel
efficient car is the ability to drive it faster while using about the same
amount of fuel. I can get good economy by just slowing down while retaining
the capability of towing a heavy trailer.

Bill Daniels