MPG on a long road trip.

[diyanich]

I am very pleased with the consumption I got on our recent trip.
I would even say am quite surprised,we did 4,014.1 kms in 8 day,5 days of driving and 3 of rest.
Almost forgot to mention.

2000 4.4i

[cfmistry]

Wow! Highest I've ever been is to 22mpg... what is your secret?!

[TiAgX5]

Originally Posted by cfmistry

Wow! Highest I've ever been is to 22mpg... what is your secret?!

The secret might be the fuel consumption calculation in the OBC needs to be recalibrated. The only TRUE verification of MPG is to log fuel volume at fill up and verify miles by GPS, NOT odo (worn tires have a reduced diameter and show extra miles on the odo).

I've gotten 24 mpg at OVER 70 mph average speed INCLUDING the gas stop, GPS verified on a few 1160 mile trip between Irving, TX. and Spring Hill, FL., only 1 gas stop during trips and 40miles dist remaining on OBC upon arrival. This was done with no AC, windows/sunroof closed, new 255-55-18s inflated to 35 psi, drafting trucks at a safe distance, coasting down for stops, (minimum brake use)!

[diyanich]

Fill up amounts are coming later today.
Same size tires,inflated to 32psi in a cold morning and 36psi after 960kms trip in a first day with 35C outside and remaining at 36psi during the rest of the trip.
Trip consisted of transcanadian highway driving with almost no city driving.A/C was on.
Cruise control set to 110 km/h almost all the times,but I don't use resume button and bring X to cruising speed with pedal and then resume.
Some members say OBC reading is inaccurate,but I find it to be pretty accurate so far.
Anyway,some more data is coming.

Originally Posted by TiAgX5

The secret might be the fuel consumption calculation in the OBC needs to be recalibrated. The only TRUE verification of MPG is to log fuel volume at fill up and verify miles by GPS, NOT odo (worn tires have a reduced diameter and show extra miles on the odo).

I've gotten 24 mpg at OVER 70 mph average speed INCLUDING the gas stop, GPS verified on a few 1160 mile trip between Irving, TX. and Spring Hill, FL., only 1 gas stop during trips and 40miles dist remaining on OBC upon arrival. This was done with no AC, windows/sunroof closed, new 255-55-18s inflated to 35 psi, drafting trucks at a safe distance, coasting down for stops, (minimum brake use)!

[TiAgX5]

Originally Posted by diyanich

Fill up amounts are coming later today.
Same size tires,inflated to 32psi in a cold morning and 36psi after 960kms trip in a first day with 35C outside and remaining at 36psi during the rest of the trip.
Trip consisted of transcanadian highway driving with almost no city driving.A/C was on.
Cruise control set to 110 km/h almost all the times,but I don't use resume button and bring X to cruising speed with pedal and then resume.
Some members say OBC reading is inaccurate,but I find it to be pretty accurate so far.
Anyway,some more data is coming.

Even with full tread tires the miles shown by the odo are inaccurate, miles need to be verified by GPS, not odo.

[motordavid]

I suspect that 21.8 mpg is close, even with doing tank fill up arith...
the key was that 68 mph cruise, imo. Get over 70, or do high 70s mph to 80 mph, and the mpg/liter per 100 will drop off considerably.

Well done; just don't have the patience for a 68 mph cruise over long distances.

We just got back from 1400 miles, and our '01 3.0 X did about the same over that 1400 miles; best tank was 22.7. Add in lots of stop and go, and the overall dropped to its usual 21 and change. But, it is what it is...the Vette gets 28-30 on every trip, but the X is 1 1/2 times heavier and is like a brick at our usual cruise speed(s) of 70-80+.
GL, mD

[JCL]

MD hit it with his 21.8 mpg calculation. That is exactly what 10.8 litres/100 km works out to, when you use the smaller US gallon measure. Based on our larger Imperial gallons here in Canada or in the UK, 26.1 is also correct, and it is what was shown by the Canadian version of the BMW computer.

All you people worrying about OBD accuracy, and tire diameter, just need to use the 21.8 mpg figure (which you have all achieved on US gallons) and see that the OPs figures are reasonable.

[TiAgX5]

Originally Posted by motordavid

I.....the Vette gets 28-30 on every trip.......

Used to see high 20s with my Viper, 3.07 to 1 final drive ratio and double overdrive (2 to 1) 6th gear ratio. Would tach 1200 rpm at 80 mph.

[Phr3d]

real mileage drops are determined by my left foot in city driving. got 21-ish in mountain driving on our trip. It ain't wunnerful, but it's pretty consistent in the 70/M ph range - wind resistance, I believe, at 78M ph and above costs us quite a bit.

we got 9.2 Mp us gal at 125 M ph, heheh.. Europe would kill us.