LLY Mileage going up hill

[rob from bc canada]

Yesterday while driving up to the local ski-hill (Mount Washington - empty except for two of us, skiis, and a bit of gear - temperature just above freezing - bare pavement all the way) I thought I would see what the fuel mileage would be going up hill.

For the first few kms (about 3 miles) the grade is about 16%, and my DIC was showing 50 l/100km which would be about 4.7 US mpg.

After that the grade levels off a bit, and the total climb would be about 3400 feet in about 16 km = 10.6 miles average 6.0% grade.

When we got to the top, average speed about 70kmh = 45 mph, the DIC read 29l/100km which would be about 8.0 US MPG.

Just for comparison, my results on regular 80% highway, 20% local driving are consistently just under 13.0 l/100 km going by the computer, and more like 13.5 l/100 = 17.5 US mpg hand calced. DIC is always about 3-5% optimistic.

OK now the question - has anyone else tried reading their results going up steep hills?? I can say one thing, it would take a whole pile of flat land miles to average down for the consumption under load.

[JohnC]

Yeah, I get about 6.5 mpg on the 3 mile trip home. I get about 40 mpg coming down in the AM :)

Did you check it on the return trip?

[rob from bc canada]

Yeah, in fact, I reset at the top, and by the time I got to the bottom, it was reading 5.3l/100k which is about 45 MPG, much like yourself.

Unfortunately the average works out to (29+5.3)/2 = 34.3l/100 which is only about 6.8 MPG

For some reason, you can't averge your mpg figures, and get a correct result.

Say you get 10 mpg going up hill, you would have to use no fuel at all on the way down to average 20.

Once you get below 10 mpg going up, you can't make it up on the return trip!!!

Moral of the story - avoid hills!!! :D

[mbmax]

Hills are no problem for me! Same mileage going both ways on our "hills". Now if only we could do something about our prairie winds