I notice that the MPG average estimate is way off what I am actually getting when fill up at the pump.

For example, recently I went 484 highway miles on 22 gallons based on my fill-up. I know, I was cutting it ridiculously close, given a fuel tank capacity of about 22.5 US gallons. This worked out to actual consumption of 22 MPG. However, the Dashboard was telling me I had average fuel consumption of 26 MPG, which was not the case. This has been my experience for the last few months, with an average LR overestimate of fuel frugality of 3-4 MPG versus reality.

Is anyone else noticing the onboard computer doesn't estimate the average very well?

 

I always trusted it...I guess I'll check mine now too.

 

I believe Land Rover is using Imperial Gallons, not US Gallons.

26 mpg (Land Rover) * 3.785/4.5 = 22 mpg.

So in the US, one has to take the LR number and multiply by 0.83 (which is 3.785 gallons US / 4.5 gallons Imperial).

Very British of Land Rover.

 

Mine consistently indicated 2 mpg higher than actual use. Then I installed tires that are about 3 percent larger than stock.
That 3 percent is about 0.7 mpg so now my computer indicates just over 1 mpg higher than actual.

 

It has been this way with many vehicles I have owned. The onboard computer always show much better economy than when calculating by hand.

Also not sure how accurate gas station pumps are.

 

As it relates to fuel economy, also remember that if you are using E-10 (10% Ethanol) that you will lose up to 3% of the stated fuel economy on the Monroney sticker that was on the original vehicle. If you are using gasoline above E10 your economy will continue to drop. As it relaters to the TDI vehicles, the higher the content of Bio-diesel will the lower the fuel economy as well.

 

Yeah, I thought it was really strange that I get almost 0 mpg when I use E10 in my TD6.

I wonder if LR is aware?

(sarcasm alert)

 

I am guessing they are not aware....ha

 

We are about 20% off the car's estimate vs. reality, so I don't think in our case it is tire sizes or type of fuel, I honestly think it is the conversion between Imperial Gallons and US Gallons. Maybe Land Rover will see this thread and be able to comment?

 

Is there a setting in the gauge computer to set US/UK units? I thought I remembered seeing one but I could be mistaken...