So, based on your calculations, Calgary, I may have been correct. I notice he failed to mention miles, km, gal, ltrs, etc. Just SOME numbers with no reference.

36.2km/gallon (US)

 

I would guess that in that post the 36 is 36mpg (metric) which is actually 30.1 mpg (US) which is 7.8L/100km.

These numbers make sense to me and seem pretty reasonable.

 

Just got back from Vegas. At 9000 miles on the meter, with 4 people + luggage, cruise control set to 75, both ways the econ display varied between 28 and 30 MPG. I think the main reasoning behind the variance was having to hill climb (Cajon pass etc..). I am very happy with the Toy's fuel economy. I did notice my mpg was worse if I kept it off cruise control.

 

Ok guys, tell me what is wrong with my car, maybe changing the wheels and tires, maybe changing the muffler. I have 20'' rims, and a chrome muffler(can't tell you the name). Last month I drove from so cal to Mo. My econ. said I got no better than 25 mpg. Could it be off? I do not think the mods would make that much of a difference. I have a 2.4 auto, any thoughts? Todd(Uma)

 

Todd (Uma) if you went from a factory 16 or 17" wheel to a 20" after market wheel, yes your gas mileage will differ because it now has to carry the extra weight of the wheel. Also did you check your tire pressure like your supposed to before going on long trips . Your supposed to check this every month or so...

 

Your wheels are heavier than stock, and the increased size throws off the speedometer. This changes shift points, and probably other things, and will affect fuel economy.

 

Actually, I did check the pressure, 35lbs as suggested, But what I did not mention, come to think of it, I averaged 74 mph. Todd(Uma)

 

I have found that the economy meter in my DIC is always 3 to 4 MPG less than actual. What I like to do is reset my trip meter when filling up, then when I fill up with gas the next time divide the gallons put back in into the miles on my trip meter. These are the only numbers I go by on my cars, I usually get between 28 and 31 MPG on my HHR with this method and 15 to 22 MPG on my explorer.

 

Thats true, but our DIC was only off by 1-2 MPG but I use it when I quote fuel mileage. I need to check it again, it's been a while.

 

If you've gone to 20's your probably also running a stiffer, low profile tire and maybe it's wider than stock as well which not only adds weight (tire and wheel) but will likely add rolling resistance (more friction between the road and tire) which will have a negative effect on your fuel economy.