Fantastic gas mileage

[dohalloran]

Most of you have already experienced this, but I continue to be impressed by the fuel mileage in my 525. I could easily have gone up to 800km on a tank had I done ALL highway driving (a mix from 80 - 115km/h).

Yes I'm on empty, but I know when I roll into the gas station, I will put in close to 67 litres. I guess it helps a bit that I changed the spark plugs a week ago.

Love this car.

[Mach540]

Most of you have already experienced this, but I continue to be impressed by the fuel mileage in my 525. I could easily have gone up to 800km on a tank had I done ALL highway driving (a mix from 80 - 115km/h). Yes I'm on empty, but I know when I roll into the gas station, I will put in close to 67 litres. I guess it helps a bit that I changed the spark plugs a week ago. Love this car.

Ummm... shouldn't the thread title be "Fantastic Gas Kilometerage??"

:0

[edjack]

That computes to 9.52 L/100 km, or 24.7 MPG, based on your dashboard numbers, unless you actually put in less (or more) than 67 L.

Any others have similar numbers for a 525iAT?

My car runs 24 MPG on highway trips, 16-18 around town, so your kilometerage is pretty good for mixed driving.

[dannyzabolotny]

What is good gas mileage? My 540it averages 15-16mpg with mixed driving, and 20mpg on an all-highway tank. These are numbers calculated at the pump, not using the OBC.

[dohalloran]

Good gas mileage is travelling over 700km on a 70L sized tank. It was showing 8.9L/100km through most of my drive yesterday. Now it shows 9.1, and from what I've read, the OBC is fairly accurate over the long haul. All highway would get me up close to 800km on a tank, to near empty. Feathery foot 95% of the time.

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Also, when you do your conversion, don't forget that our gallon is 4.546 litres, whereas US is 3.785 L.

[pleiades]

Good gas mileage is travelling over 700km on a 70L sized tank. It was showing 8.9L/100km through most of my drive yesterday. Now it shows 9.1, and from what I've read, the OBC is fairly accurate over the long haul. All highway would get me up close to 800km on a tank, to near empty. Feathery foot 95% of the time.

- - - Updated - - -

Also, when you do your conversion, don't forget that our gallon is 4.546 litres, whereas US is 3.785 L.

That's just slightly over 26 mpg. Fantastic?

[schatzy62]

... from what I've read, the OBC is fairly accurate over the long haul.

Not on all cars.

My normal daily drive is 22 miles (11 each way) for work. 9.2 miles is highway at 65 mph and 12.8 is back roads of 30-50 mph.

ODBC after "not" resetting it for 5 tanks shows 21.3 mpg. Calculations one miles/gallons at the pump shows 16.29, 17.79, 16.23, 16.84, 17.15 (16.86 average), Okay so I am a little heavy on the peddle, but I rarely have anything less than 16 mpg. All highway miles/gallons calculations are 27 to 29 mpg at 70 mph.

My ODBC for normal everyday driving is always 3+ mpg high.

During longer test periods of 15+ tanks of gas it still reads over 3 miles per gallon high.

On long 2500 mile vacation highway only runs it is off by about 1.8-2 mpg high.

Now on my MINI Cooper it is even worse it is normally off by 5 miles per gallon for city driving and and about 2 miles per gallon off on long (2500 mile) highway runs.

[BimmrMeUpSnotty]

I went on a 550 mile trip two weeks ago in my 528 wagon and got 24.9 mpg, That was with long spurts of 90mph stretches. I got new plugs for the car, problem is, they're sitting on top of my toolbox....

My 530 usually gets 25 to 29mpg. The 540 usually about 17 to 19.

[Mach540]

and from what I've read, the OBC is fairly accurate over the long haul..

Also, you can adjust the calibration for the OBC using test#19 I think. Anywhere from 75% to 125% of what it "Thinks."

[BimmrMeUpSnotty]

Sheesh, old school math in yer head works purdy good too.

[Mike WW]

I've seen one tank just over 30MPG on the 525it and one on it's predecessor the 528it. OBC and calculated were similar so I'm calling it valid. That would be just over 800km on a tank. And I've heard the 530i's do better than the smaller 6's. Yes, the M5X engine series is impressive for both efficiency and performance. E39s are slippery, aerodynamically, but not light either, especially the tourings.

[Dave Sal]

I must be a lead foot, cause I only get about 18mpg of city driving. Also, no one mentioned that the fuel pump will die an early death if it overheats from lack of fuel in the tank.

[Mike WW]

I must be a lead foot, cause I only get about 18mpg of city driving. Also, no one mentioned that the fuel pump will die an early death if it overheats from lack of fuel in the tank.

My 2000 touring was down to about 19 in an easy commute when the Vanos needed a rebuild, and granted I don't live in an urban environment, but other than that I don't think I've ever seen under 20. And rarely that.

[Uturn540]

Round trip from just west of Austin, TX to Albuquerque, NM using actual mileage and fuel use 27.5mpg at 72mph average. Computer read out was 28.5mpg. Used the figure to adjust the OBC calibration. Average 23.5 in local driving. Guess I got on of the stingy V8's.

[edjack]

Good gas mileage is travelling over 700km on a 70L sized tank. It was showing 8.9L/100km through most of my drive yesterday. Now it shows 9.1, and from what I've read, the OBC is fairly accurate over the long haul. All highway would get me up close to 800km on a tank, to near empty. Feathery foot 95% of the time.

- - - Updated - - -

Also, when you do your conversion, don't forget that our gallon is 4.546 litres, whereas US is 3.785 L.

You reported apparent liters to fill, and I converted it to US gallons, based on your dashboard odo. Your gallon has no relevance in my calculation.

[auaq]

Strange. How are you guys getting double digit numbers? I must be doing it wrong because I average around 12.67gal/smile daily. Not going by what the OBC says but using my algebraic head.

[geargrinder]

Most of my M5 owning buddies struggle to keep it up in the teens Asim, so, yeah.

I try not to calculate for the 540 but if I granny it and keep the blower quiet maybe I'm in the high teens. Granny and highway but not too fast highway that is.

[dannyzabolotny]

It's tricky to get good mileage in a 540i touring because it has a 3.15 diff ratio versus the 540i sedan's 2.81. That means at 80mph you're spinning closer to 3000 rpm which uses up more gas.

[Mike WW]

It's tricky to get good mileage in a 540i touring because it has a 3.15 diff ratio versus the 540i sedan's 2.81. That means at 80mph you're spinning closer to 3000 rpm which uses up more gas.

You're kidding. On the 540 which has loads of power they put in a lower diff to compensate for the extra weight, but on the emasculated 525it they keep the same diff as a 2.8 sedan?

[XAlt]

You're kidding. On the 540 which has loads of power they put in a lower diff to compensate for the extra weight, but on the emasculated 525it they keep the same diff as a 2.8 sedan?

No, because the 3.15 got applied en-masse for the Vanos auto 540.

[Mike WW]

No, because the 3.15 got applied en-masse for the Vanos auto 540.

Ok, I feel slightly better then. At least until I'm going up a mountain pass at 4500 pounds with a little 2.5 working as hard as it can.

[6spd540]

Round trip from just west of Austin, TX to Albuquerque, NM using actual mileage and fuel use 27.5mpg at 72mph average. Computer read out was 28.5mpg. Used the figure to adjust the OBC calibration. Average 23.5 in local driving. Gues I got onr of the stingy V8's.

That's about what I get with mine except if I have a lot of in town or traffic driving mine drops down to 19-21. I also live/drive in areas with lots of hills.

My OBC is always really close to to actual, within a few points.

Sent from my Pixel XL using Tapatalk

[geargrinder]

You're kidding. On the 540 which has loads of power they put in a lower diff to compensate for the extra weight, but on the emasculated 525it they keep the same diff as a 2.8 sedan?

No, because the 3.15 got applied en-masse for the Vanos auto 540.

Still I'm with Mike. Diff setups for USA were semi-arbitrary IMO. You WOULD think the little non-V8-torque motor would get the lower gearing. Oh and the 540 Tourings got special flanges and axles too, how totally random. And before you go all "extra weight", naww. Not that significant. If it was you could think up all other kinds of excuses to use diffferent parts for the 540 Touring but that's about all that's different back there. "Semi-arbitrary" is the exact right word. You'd think at least the sedan M-sports mighta gotten the bigger flanged axles but nope.

[BimmrMeUpSnotty]

They did it to give all the different versions their own character.

[itsbrokeagain]

I must be a lead foot, cause I only get about 18mpg of city driving. Also, no one mentioned that the fuel pump will die an early death if it overheats from lack of fuel in the tank.

Not exactly true. Any car with a saddle tank, when you get below the driveline, the pump is always using whatever's in that corner of the tank.

In the case of the X5, it sits in about a gallon sized recession in the passenger side of the tank, and when you go below 3/4, the pump is only sitting in 1 gallon of fuel while the rest of it is suction-jetted over from the other side.

Even with range reading empty, you should still be able to go another 10-15 miles, which is about a half gallon...