325i mpg

[maf260]

I've just calculated the mpg I'm getting on my 325i cabby - 23mpg with a mix of driving, but a few short journeys within that. The car has had a recent service, has a BBTB, a mild chip from Speedtouch and a stainless exhaust system (not manifold). Does this sound about right?

[capri_rob]

Sounds about right. Short journeys will hammer fuel economy.


You can probably get better MPG than that if you concentrate on driving for economy, but you have to drive pretty gently to get 30+ MPG out of an M20 engine.

[Ant]

my auto will do no worse than 31 Mpg

indeed will do 36 on a run no issue, not nursing either

[maf260]

Any obvious things to check then Ant? That's quite a big difference between our cars. It doesn't feel like anything's wrong or not running well, but I thought I should get better economy than 23mpg. A fill up is about 40 litres - is the tank really that small?

[SeymourCake]

Ant how do you get so high mpg??

I only get 20ish mpg around town on my 325i auto cabby.

[SGP]

20 ish is normal. Fuel economy wasn't such a big issue 2 decades ago.

[CaesarBob]

my auto will do no worse than 31 Mpg

indeed will do 36 on a run no issue, not nursing either

Is that with one of your jekyll & hyde 2 map chips and a longer diff?

[octanejunkie]

You wanna try running a tuned up M30 six, with a crippling 15mpg. After running that monster an M20 seems like an Econetic diesel!

[casper8r]

I've been running a well-maintained 325i auto for a last year or so and my average mpg according to OBC is slightly below 24 mpg (this includes a 3000+ mile roadtrip).

All in all this makes me feel good about the planned purchase of e34 540i - shouldn't be much worse

[charlE30]

Any obvious things to check then Ant? That's quite a big difference between our cars. It doesn't feel like anything's wrong or not running well, but I thought I should get better economy than 23mpg. A fill up is about 40 litres - is the tank really that small?

You've still got 1/3 of a tank left, 63lt's is what they hold you'll often get to the red and have loads still left.

My other halfs 325i tourer averages around 22mpg but her's is nearly all stop start around town. My 325ia averages around 27mpg but mine is all motorway at high speed.

On my M30B35 I can get upto 30mpg on a run and average around 22mpg on mixed.

Ultrasonically cleaned injectors are a good place to start for improving the overall performance inc mpg... have a look in the traders section.

@Ant what and how do you manage those mpg figures?

HTH

Charlie

[Ant]

its on an MPG optimised chip.

low load maps are lean as poss, high load and WOT and standardish....

to run lean @ low throttle without a stutter I've added 3 deg timing in this area.

My Mrs does 108 miles a day commute, hence the tweaks.

Drives like stock BTW

[maz1]

Ant how much would it cost to get the same chip for my 325i sport

Thanks

[charlE30]

its on an MPG optimised chip.

low load maps are lean as poss, high load and WOT and standardish....

to run lean @ low throttle without a stutter I've added 3 deg timing in this area.

My Mrs does 108 miles a day commute, hence the tweaks.

Drives like stock BTW

I would be very interested in one of these aswell for my Mrs (standard 325i manual tourer)

Charlie

[ivqii]

In my auto Baur with aircon i got 22

My manual cabby no aircon I get 28

As the cabby is heavier it shows what auto and aircon did in those days - not so bad in modern cars

[DaveD]

about 25 round town but I have had 40 on pure motorway but generally on longer distances about 34