[Mark M]

Originally Posted by Persian Whisperjet

Very helpful.

There is probably something to be said about winter fuel formulation being (supposedly) less energy dense.



Re the max range, in looking at my Fuelly logs I have put 16.4 gallons in my car more than once -- probably not advisable but possible. Given that you could hit 42.7 mpg and do 700 mile son one tank.

Theoretically it may be possible to hit 700 miles on a tank...but realistically who wants to chance running the tank that low merely for bragging rights? You could suck up debris from the tank floor, or run out of fuel before you hit a station, or worse yet, over-heat the in tank pump.

I think most of us in the real world are seeing 500 to 600 per tank before filling up without taking the above risks.

However for those seeking a challenge...try and repeat this one from the interwebs. Chicago to NYC = 49mpg on one tank. And they were on a sport pack car with less than ideal rolling resistance tires.

http://www.cleanmpg.com/community/in...threads/21026/

[nicklockard]

Originally Posted by Persian Whisperjet

Very helpful.

There is probably something to be said about winter fuel formulation being (supposedly) less energy dense.



Re the max range, in looking at my Fuelly logs I have put 16.4 gallons in my car more than once -- probably not advisable but possible. Given that you could hit 42.7 mpg and do 700 mile son one tank.

Really good point. Winter fuel is 4%-8% fewer btu's of heating value by volume than summer fuel. You'd definitely want to make the attempt on summer fuel.

Published tank capacity is 16.1 gallons. So the neck holds an additional .3 gal?

[Persian Whisperjet]

Originally Posted by Mark M

However for those seeking a challenge...try and repeat this one from the interwebs. Chicago to NYC = 49mpg on one tank. And they were on a sport pack car with less than ideal rolling resistance tires.

Wow, that is off the hook!

[Persian Whisperjet]

Originally Posted by nicklockard

So the neck holds an additional .3 gal?

Seems unlikely. I suspect BMW doesn't want people running down to empty because of the cooling properties of the fuel for the fuel pump.

[lnxguy]

Originally Posted by Persian Whisperjet

Seems unlikely. I suspect BMW doesn't want people running down to empty because of the cooling properties of the fuel for the fuel pump.

Don't forget your pumping hot fuel back into the tank the entire time anyhow. I doubt BMW is worried that much...

If they were really worried about cooling, they would have installed a fuel cooler from the factory (Like VW did on the PD cars)

[Persian Whisperjet]

This thread got me thinking about max range and whether 800 miles on a tank is baloney. My previous max, on a trip from St Louis to D.C., was 690 miles. I had a lot of driving to do this weekend, so I set off on a 200 mile trip to West Virginia with the goal of keeping the speed between 65 an 70.

Tires had 35 psi front and 43 psi rear.

I ended up with 45.1 MPG (computer) so well short of the claimed 50 mpg. Note: Whereas my stock mpg estimates tended to be about one mpg pessimistic, since my JR Stage I the estimates have become uncannily accurate.

But wait, as they say. On my return leg I took a longer (250 mile) windier road with more elevation changes, crossing into Pennsylvania on I-81 toward Harrisburg, then back down and east to Baltimore on I-70, then 695 then south on I-95 toward Annapolis.

On this leg I kept the speeds between 60-62 mph, as challenging as that was, and actually averaged exactly 50 mpg over 250 miles.

This car does not cease to impress. White it takes huge willpower to drive 60 mph, this car can literally cross the country on 3.5 tanks of fuel.

[lnxguy]

Using nothing but the computer for mileage estimates is a great way to get very inaccurate numbers.

Fill the tank to the brim, drive, fill the tank to the brim, do math, done.

[Persian Whisperjet]

Originally Posted by lnxguy

Using nothing but the computer for mileage estimates is a great way to get very inaccurate numbers.

On the contrary, I have found the OBC numbers to be extremely accurate, especially on a longer (250 mile) drive. If you click on my Fuelly you will find that I enter the OBC mpg estimate into the comments field and it is typically within 0.2 mpg.

[lnxguy]

Realistic MPG numbers should be an average over an entire tank, not a single trip, it's way too easy to pad the numbers this way.

[Persian Whisperjet]

Originally Posted by lnxguy

Realistic MPG numbers should be an average over an entire tank, not a single trip, it's way too easy to pad the numbers this way.

Not sure how you define "realistic MPG numbers." Perhaps you mean mileage a driver can expect in everyday use, in town, on the highway, etc?

The article about Chicago to New York -- and my post -- are clearly about something entirely different, i.e., eking out the highest possible mileage on a single long drive.

Apples and oranges.

[lnxguy]

Drive the entire tank, do some math and calculate your numbers. Can you average that over an entire tank? I could say my car gets 60mpg on my 15mile commute which is almost all downhill with a killer tail wind. Sure the numbers sound great but it's not very realistic. I'm sure this car is capable of great mileage, I don't think a single 250 mile trip is proof of that however.