With a 500lb motorcycle trailer from U-Haul and a 500lb bike on it (so about 1,000 lb) in tow, on flat roads, at about 50-55mph, I managed 40mpg in my Insight. Not bad at all. With a 1,200lb trailer (5x9' utility trailer from U-Haul) and a 500lb bike on it, the mileage drops to 28-29mpg at 50mph on flat roads. Not good. Trailer tires inflated to 60psi.
You don't want hills - basically, keep the RPM around 2,200-2,500, meaning the speed varies between 40 and 60mph, depending on whether it is a gentle uphill, flat, or downhill.
Anything over 500lb weight is pushing it, but up to 1,000 seems to quite reasonable on flat roads. It's no worse than having 3-4 people in the car, if the trailer is loaded courtly. Keep the speed down, because the rear end is light and your handling in an emergency braking during a turn will be affected. Straight line and gentle turn braking is fine.
Over a 1,000lb in tow will shorten the transmission life, probably, and I think is not really safe in an emergency situation, where the rear end might get loose (unlike with 1,000 in the car, which loads the tires and improves traction).
2011 Honda Insight Base
Last edited by Kocho; 07-07-2014 at 06:01 PM.