Fuel consumption towing a trailer by PaulT

We make regular trips down to SW France. Consumption is always at least 45 mpg.

The trip we have just been on we towed down an 8' x 5' x 6' box trailer with a GVW of 1580kg.

Going down it was full so must have been near its GVW. Coming back it was empty so probably weighed about 600kg

I was surprised at the lack of difference in consumption:

Going down full - 26.61 mpg
Coming back empty - 28.17 mpg

Admittedly, probably towing about 5 mph faster coming back but I expected the difference to be much greater.

The other odd thing is that the car usually shows less mpg on the display when driving without a trailer. However, with the trailer it showed more mpg.


"Don't think of them as problems, think of them as opportunities."
"OK, I think I've hit an insurmountable opportunity!"


Posted 09 Dec 2010, 08:21 #1 

Fascinating results!

Since you were pulling at least another 25%, weight-wise, going to France, you would imagine there would be
a commensurate increase in fuel use.

Maybe it is something to do with momentum, or engine load???

I really don't know... but if anyone can explain this phenomenon I'd love to hear it.


Posted 10 Dec 2010, 01:46 #2 

User avatar
The air resistance will be more important than the weight, I think.

Posted 10 Dec 2010, 16:01 #3