z4 fuel consumption

[DavidC2]

Hi, just bought a 2007 Z4 2.0 with 40,000miles. I'm concerned about the fuel consumption. This seems very poor (20mpg measured by hand and I'm not driving hard or in town). Interestingly the electronic mph trip counter is stuck on 12mph. All the other readings (temperature, trip distance etc.) seem fine. As does the car in general. So, should I be concerned, and if so, what should I start looking for? Any help would be great - thanks.

[Locknut]

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DavidC2 said:

Hi, just bought a 2007 Z4 2.0 with 40,000miles.

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DavidC2 said:

I'm concerned about the fuel consumption. .

Cart before horse?

[flight147z]

If it's useful - my 3.0 will do 30mpg seemingly regardless of how I drive it (which is a mix of town and motorway) therefore 20mpg does sound low under any conditions

[Hoofy]

May need to install this on your phone and monitor for a few weeks: https://play.google.com/store/apps/details?id=ch.s...

[anonymous-user]

We had a March 08 Z4 from new until the end of 2014.

All through that time it averaged mid/high thirties, on a mix of short and long runs.

Would easily do well over 40 on a gentle cruise.

[mon the fish]

Either your engine is broken, or the OBC is broken.

Measure it the old-fashioned way (distance from a brimmed tank) and see what you get

[dhutch]

flight147z said:

If it's useful - my 3.0 will do 30mpg seemingly regardless of how I drive it (which is a mix of town and motorway) therefore 20mpg does sound low under any conditions

This is certainly how I find my 330ci.

You can do 40 doing 55mph on an dual carriageway, or 25mph trashing it, but it all nets out to 30mpg on the OBC for each tank.

I fine my OBC to be about 1mpg more optimistic than brim to brim.

Daniel

[Rick101]

2010 Z4 3.0 NA Auto here.

Avg 30MPG

[Hoofy]

Just had a thought - how are fluid levels? Any leaks? Any smells when the engine is warm?

[DavidC2]

mon the fish said:

Either your engine is broken, or the OBC is broken.

Measure it the old-fashioned way (distance from a brimmed tank) and see what you get

Hi, I did measure it the old fashioned way - hence my concern!

[twizellb]

I have a z4 2.0 and last month went round France in it, the best tank full was 43.2mpg measured the old fashioned way.
Filled up 30mls from Dunkirk and that tank got me home to 20mls past Newcastle, just
There must be something wrong with yours if those figures are correct.

[wiggy001]

My 3.0 Sport Auto Coupe gets about 340 miles to a tank around town, 400 when it's mostly motorway commutes.

[dhutch]

wiggy001 said:

My 3.0 Sport Auto Coupe gets about 340 miles to a tank around town, 400 when it's mostly motorway commutes.

Which is about the same as I get in my manual gearbox. Within the experimental accuracy.

Daniel

[jonamv8]

my Dads got one, this is definitely wrong, I'd get it checked out

[SebringMan]

Is your a 4 pot or a 6 pot Z4?

If the latter they are not amazing on fuel by any stretch. It's one reason I have avoided buying one. I learned my lesson with an E32 730i many moons ago ; man that was bad!

[Mr Tidy]

Definitely not right OP!

I have a Z4 Coupe, so it's a 3.0Si, and my OBC shows an average of 34.0 mpg.

Admittedly it doesn't get used to commute, but it does get used properly (OBC also shows an average speed of 41.2 mph).

I hope you can sort out why yours is so thirsty.

[motoroller]

SebringMan said:

Is your a 4 pot or a 6 pot Z4?

If the latter they are not amazing on fuel by any stretch. It's one reason I have avoided buying one. I learned my lesson with an E32 730i many moons ago ; man that was bad!

The 2.0i are 4pot. Very economical. Mine would give me 50mpg when the M3 had 50mph speed restrictions in place!



Although when hoofing it that would go to low 20's...

Any weird smoke / smells / fluid consumption on the engine?

[Hoofy]

motoroller said:

Any weird smoke / smells / fluid consumption on the engine?

That's what I asked, too. What's your thinking, before I give mine? Not that the OPer has replied to my question.

Edit: my experience with a 4x4 with a leaky washer bottle: when the engine got hot, it heated up the engine bay and it stank of hot cleaner fluid both around the car and in the cabin. The MPG was reading as low as an average 11mpg between fuel ups. Now that I've sorted out the issue, I'm finding I get an MPG around town of just over 20.

Edited by Hoofy on Wednesday 4th October 12:12

[G600]

DavidC2 said:

Interestingly the electronic mph trip counter is stuck on 12mph.

Have you reset it? Press and hold the trip button until it clears, it's probably just a very long term average, it doesn't reset automatically.

[Z4MCSL]

I have a Z4 3.0si and I struggle to get anything above 20.6 - that being said I live in London so I also struggle to get my average speed above 25mph...and I drive like a douchebag. Even so it does seem particularly bad.