Accurate on board computer MPG

[GazHyde]

I don't think I've reset the OBC for at least a year, possibly more and today when I pulled in to Sainsbury's for a tank of super unleaded it was reading 27.8 mpg. When I got to the office I worked out the MPG manually and that came out at 27.81 mpg (267 miles divided by 9.6 gallons).

That's a difference of 0.01 mpg. Never had an OBC calculation on any car I've owned get close than about 2 mpg difference.

 

[EnthuZiaZT]

That's encouraging Gaz, I've always taken the MPG figures shown on the dashboard with a pinch of salt. Not saying that all BMWs will be as accurate as yours. If mine was within 2 MPG I'd be happy.

Mike

 

[Jack Ratt]

I calculate my mpg at every fill up by miles covered against fuel used. Miles divided by litres of fuel. multiplied by 4.54 = mpg

My 2.8 auto is currently returning 29.5mpg. My OBC says 32mpg

I hasten to add that I drive like my Grandad

 

[Dino D]

I calculate my mpg at every fill up by miles covered against fuel used. Miles divided by litres of fuel. multiplied by 4.54 = mpg

My 2.8 auto is currently returning 29.5mpg. My OBC says 32mpg

I hasten to add that I drive like my Grandad

That's a handy formula, save me using an online calculator.

29.5mpg on an auto 2.8????
You should see a physio about your right leg Or get some heavy safety boots when you go zedding!

It's proven that using full throttle and all the revs in at least the first two years on regular basis is good for your health.

 

[Shelly]

That's good going
Don't know how many miles mine do
I just put the petrol in and go

 

[andyglym]

Good going that. Not carried out anything scientific but on a long run (full tank) my OBC states anything from 27mpg -31mpg depending on driving style, It appears to be not a million miles out so happy with that.

 

[Grumps]

Mine tends to sit around 28-31 although I've never checked to see if this is a decent view if what is actually happening although it seems in line with what folks are saying. The firm I work for now use our dash reading as gospel as we are monitored by it. It also has a target figure put in by the gaffer as he thinks it will help us achieve a better mpg figure. The engine in my truck is a 13ltr straight six 410bhp. He wants me to hit a target of 11.5mpg, a present I'm running at 8.5mph!!

 

[oldcarman]

And just how much more than you does this guy make each payday @Grumpy? I'd think 8.5 was a pretty accurate number considering all the factors involved. JIM

 

[smiffy]

I think my OBC must be faulty. Has never read higher than 22mpg in my ownership.

Or maybe its the Cold, Warm, FAST, Stop, driving style on country roads that does it?

 

[Grumps]

And just how much more than you does this guy make each payday @Grumpy? I'd think 8.5 was a pretty accurate number considering all the factors involved. JIM

He doesn't make money he loses it at the rate of £6000 a week on diesel bill. DHL recently took over the transport arm of the business and the guy that put the tender in for the job quoted us doing 11.5 to the gallon. Wagon and drags do not do the same mpg as an artic. 25 lorries running at 3 to the gallon less than quoted on the mileage we do aquates to a huge loss, as it's DHL's cock up eurocell are laughing for the next 5 years as their tied into the contract. Ooooops!

 

[oldcarman]

Makes you wonder where they find these clowns doesn't it?? JIM

 

[Grumps]

Makes you wonder where they find these clowns doesn't it?? JIM

He no longer works for DHL so I'm told Jim!

 

[GazHyde]

My MPG has improved by about 3 since changing the cam sensor. I don't even want to think about how much that little thing has cost me...

 

[Grumps]

My MPG has improved by about 3 since changing the cam sensor. I don't even want to think about how much that little thing has cost me...

That's a massive change Gaz as you run yours daily..just goes to show keeping your car right works wonders.

 

[Redline]

The readout in the LR reads about 1mpg light and always has consistently.
Thought I'd reset the OBC in the Zed last week and for the first two days I was reading 16.1 mpg. Oops.
Got it back up to a total distance of 325 miles over the last few days and that includes a bit of a blast round the lanes in Leicestershire on Sunday.

 

[Redline]

Mine tends to sit around 28-31 although I've never checked to see if this is a decent view if what is actually happening although it seems in line with what folks are saying. The firm I work for now use our dash reading as gospel as we are monitored by it. It also has a target figure put in by the gaffer as he thinks it will help us achieve a better mpg figure. The engine in my truck is a 13ltr straight six 410bhp. He wants me to hit a target of 11.5mpg, a present I'm running at 8.5mph!!

You could get the truck up a bit but you'll only be able to carry a couple of small boxes at anyone time.

 

[Grumps]

You could get the truck up a bit but you'll only be able to carry a couple of small boxes at anyone time.

That's the problem Ian, we don't carry little boxes!

 

[t-tony]

I'd best get the handbook out and see where the OBC is on my car. Or maybe not, I might scare myself, currently, when it needs fuel I put some in. I did notice today that the Z3 fuel gauge drops a bit quicker than the Z4 if you apply the right foot.

Tony.

 

[oldcarman]

Bigger tank size @t-tony?? JIM

 

[Redline]

I'd best get the handbook out and see where the OBC is on my car. Or maybe not, I might scare myself, currently, when it needs fuel I put some in. I did notice today that the Z3 fuel gauge drops a bit quicker than the Z4 if you apply the right foot.

Tony.

Going from a car that did 700-800 miles between refills down to one that does 500 and then just 300 is a shock and takes a little getting used to.