Trailer Towing Mileage

[Roverguy1]

Just back from a short five day holiday. Left from just north of Toronto and drove to Lake Superior (two hours north of Sault Ste Marie) and back with our teardrop trailer. Even with all the large hill climbs, my mileage went from 10.9 lt per 100 kms to 11.4 lts per 100 kms. I thought this was pretty good for the added weight. The trip was between 9-10 hours each way and my speed varied from 80 - just over 100 kph.

 

[Tuc4R]

What does lt and kms mean? :bounce:

 

[mogg851]

Ok, if this site is correct (Convert Liters per 100 Kilometers to Miles Per Gallon (US)) I don't even get that milage NOT towing. I took our teardrop from OR to AZ and we got 10ish mpg to 13 mpg. Granted we have a RTT on the trailer and had a headwind on the way down, thus the 10, but I thought I was doing pretty good with those numbers. How are you managing that high? Tell us your secrets please.

 

[jhguth]

even when i was bone stock i don't think i ever saw better than 11-12 liters/100km (and 11 would have been no traffic driving like a granny in the slow lane), how tf are you doing better than that while towing?

 

[Roverguy1]

Well, I track a few fill-ups over the next couple weeks and see just how accurate the truck mileage indicator is. I did that when I first bought the truck and it was pretty close. That said, I typically drive secondary roads and average between 90-100 KPH. I also keep an eye on the ECO light and try to stay within its limits

 

[Jetboy]

The speed is the key here I think. I get around 11-12mpg towing my small trailer at 80mph - or 130k/hr. At 60mph (95k/hr) I'd get closer to 18, sometimes higher. At 50mph (80k/hr) I could pretty consistently get 20mpg.

Wind resistance is a function of velocity squared. If the resistance at 50mph is set as 1.0, the resistance at 60mph is 1.41 (41% more energy required) and by 80mph it's 2.6 (160% more energy required).

If we use a baseline of 20mpg at 1 unit of wind resistance being 50mph and thermal efficiency remains constant you'd expect to get 14.2mpg at 60mph and 8mpg at 80mph. Wind resistance is not the only resistance, so this drop isn't quite inline with reality, but provides a bit of a baseline on how much the increase in speed changes the fuel efficiency.

 

[Mg2014]

Impressive - I just drove 300 miles from Vancouver to Astoria and got 22l per 100km or about 11mpg - 4200lb TT and steady 60-65 mph