Z4M - Fuel Economy?

Z4M - Fuel Economy?

Author
Discussion

msportpanda

Original Poster:

698 posts

132 months

Wednesday 1st December 2021
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Before I start, I know it's a fastish car with an old engine and it's not supposed to be fuel efficient!

I've taken it on some longer drives, did just over 200 miles on Saturday and it was mostly motorway at 70ish. I couldn't seem to get it over 28mpg. Just want to check if other Z4M/S54 owners get a similar figure or if mine's a bit out?

Fwiw it's on 19" CSL's and MPS4S's which might impact?


essayer

9,621 posts

201 months

Wednesday 1st December 2021
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mine was on 18"s but I don't ever remember getting 30mpg+, sorry!

It's worth it though hehe

e46m3c

875 posts

162 months

Wednesday 1st December 2021
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yup. 28 is right.

Fishy Dave

1,049 posts

252 months

Wednesday 1st December 2021
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Excluding track miles I used to average 24mpg commuting, with a mixture of slow warm up, heavy traffic then some fast B roads, about 50 minutes each way.

Mr Tidy

24,313 posts

134 months

Wednesday 1st December 2021
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I've never managed 30mpg in mine either. biggrin

The average on the OBC got reset when I fitted a new battery in April and 2,000 miles later it's showing an average of 27.1mpg, but as it's a weekend/fun car that's nearly all 5-+ mile trips on Motorways and A Roads outside of rush hours. For what it is I'm pretty impressed with that!

msportpanda

Original Poster:

698 posts

132 months

Thursday 2nd December 2021
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Brilliant! Glad mine's not alone.

It's worth it to be fair, the S54 is incredible!

cerb4.5lee

33,599 posts

187 months

Thursday 2nd December 2021
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I only got 23mpg from mine. However it was only used as an occasional fun car though, so when I went out in it I would open it up a bit. driving

As a comparison I use my 370Z Roadster in the same way, and that only does 22mpg as well. So I think it is normal for the old fashioned NA engines to be pretty thirsty I reckon.

mmm-five

11,437 posts

291 months

Saturday 4th December 2021
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I only calculate via fill-ups though, as I find the OBC under-reports MPG a little.

As high as 32mpg on a very steady run from Dunkerque to the Ring (filled up in Dover and filled up again at Ed's)...but an overall average of 26.6mpg (track days, commuting, ring trips, weekend blasts, etc.) tracked over 81,000 miles (started in 2012, 4 years after I bought it).





19" CSL wheels might be lighter than 18" 224M wheels, but the smaller rolling radius (3.0% smaller if you've used standard 265/30r19 rears) might have a small impact on MPG.

To show how good it can be on easy throttle application cruising, here are my best returns...


...and for those who say I should drive it like it's meant to be driven, here are my worst returns...


Edited by mmm-five on Wednesday 22 December 10:29

Beedub

1,993 posts

233 months

Sunday 5th December 2021
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terrible. lol

Pereldh

591 posts

119 months

Monday 6th December 2021
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Mine's very thirsty too...
For all its achievements, the S54 is not very efficient nor durable! biggrin

Polarbert

17,928 posts

238 months

Tuesday 7th December 2021
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My car is stuck in American MPG being the inferior Yank model. But I've been averaging about 21mpg over the last god knows how many thousands of miles. I just wish the tank was slightly larger. But it is so much fun I rarely care. Petrol is getting on the pricier side here at the moment.

ian in lancs

3,821 posts

205 months

Tuesday 7th December 2021
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My Z4MR has averaged 25.467mpg over 60,000 miles

CRA1G

6,774 posts

202 months

Tuesday 7th December 2021
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I can genuinely say I've never checked....hehe just fill mine up and dive it whenever I can...driving

mmm-five

11,437 posts

291 months

Tuesday 7th December 2021
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CRA1G said:
I can genuinely say I've never checked....hehe just fill mine up and dive it whenever I can...driving
I collected the receipts for expenses, so it was but a minute's work to put the figures into Fuelly at the same time...but when you're in the north of Scotland, and pressing on, you tend to want/need to know, so you can schedule/plan stops for Super Unleaded.

fido

17,281 posts

262 months

Tuesday 7th December 2021
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S54 has fantastic BMEP for a naturally-aspirated engine. Ditto the S65 V8 that came after it. Neither does fantastic MPG but for a weekend car it's okay.

Cheburator mk2

3,066 posts

206 months

Thursday 9th December 2021
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Had a Z4MC from new and kept it for 5yrs and 50k miles. Brim to brim I used to average 25mpg - weekend trips to Europe, about 10k Ring miles as well as normal track days and trips to Scotland and Wales. On a run at steady 75mph (3000rpm) i could just about eke 30mpg.

I am on my 7th E46 M3. On a run at the same speed as above I easily see 33 to 35mpg. Best ever was a trip from London to Sofia - observing the speed limits and mostly motorways in France, Italy and Greece - was 37mpg.

I think the S54 is a fantastic engine and very frugal when driven sedately. Perhaps the E46 body is more aerodynamic than the coupe.

Had an E61 M5 at the same time as the Z4MC - that put fuel economy in perspective. 20k miles in 2yrs, 16mpg...

flimper

565 posts

190 months

Saturday 11th December 2021
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I'm getting 22.6 mpg over the last 73 fill ups and 15k miles

CousinDupree

783 posts

74 months

Tuesday 14th December 2021
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27mpg over the last ten years, half urban in London.


a340driver

304 posts

162 months

Tuesday 14th December 2021
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Not sure why it's so bad

1 was that day, 2 is the long term average.

Edited by a340driver on Tuesday 14th December 15:02

sixspeed

2,061 posts

279 months

Wednesday 22nd December 2021
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28 sounds spot on really.