2.0 Z3 Fuel Consumption

lowflyer · Post by **lowflyer** » Tue 08 Feb, 2005 18:33

Hi! Long time viewer first time poster and all that so go easy!!

Quick question regarding fuel consumption for those in the know...

I've got a 2000 2.0 Z3 which is doing about 24 mpg. Is that about par for the course? Just had it fault code and emissions tested as the dealer recoked that 29-31 mpg would be more like it but nothing showed up on the test. Maybe its just the way I drive it??!!

Oh and is the difference between 95 and 98 octane fuel significant??

Cheers!

garyw · Post by **garyw** » Tue 08 Feb, 2005 18:36

My 2.0 used to return 25-28mpg depending on how it was being used, oddly enough my current car can return 28mpg on a run.
There are plenty of threads on RON and Optimax(Ron 98),
I do return a higher mpg from using Optimax and would always use it where I can.
garyw

JohnBag · Post by **JohnBag** » Tue 08 Feb, 2005 18:49

i was gonna post the same question lol, i get about 24 to 25 mpg which i think is low!!! i have a stuck thermostat at the moment and aparently that affects the mpg, hopefully when fixed i should get more. Does your heater work ok????

tried to drive like im driving miss daisy but still get the same mpg

anyone else had problems with their heaters and it affects their mpg???

Bloke · Post by **Bloke** » Tue 08 Feb, 2005 19:09

Well I've had my 2.0ltr for nearly 5 years now, and I used to get 20mpg around town and 24 on longer stretched, I do however have a very heavy right foot, as most of the guys here would agree with!!!

Now im on Shell Optimax, I seem to be getting much better mileage

Bloke

komis · Post by **komis** » Tue 08 Feb, 2005 19:25

I get around 22mpg in town and 37 on the motorway with my 1.9... On Optimax that is and without pushing it much, i admit i drive like an old lady around town and whenever there are lots of cars around.

GROMMIT · Post by **GROMMIT** » Tue 08 Feb, 2005 21:47

I've got a 2.8 and I regularly get between 28-31 out of it. It depends on how you drive it. Stay below 2.5rpm and get through the gears quickly and you should easily get more than 25ish. I can give mine a bit of a thrashing and it rarely goes below 25.

Devon Z · Post by **Devon Z** » Tue 08 Feb, 2005 22:51

Had my 99 2.0 since new and I'm only going on what the computer say's average 24/28mpg. I've tried Optimax and Esso Ultima and found little improvement but find it much more lively on super unleaded.

Steve,

RobBruce · Post by **RobBruce** » Wed 09 Feb, 2005 00:51

lowflyer wrote:Hi! Long time viewer first time poster and all that so go easy!!

Oh and is the difference between 95 and 98 octane fuel significant??

Cheers!

First of all, hello and welcome!

Second, YES, most people find a significant difference. All those who plan cruises know you also have to plan where the nearest Shell is so everyone can fill up on Optimax!

If you're getting 24mpg all the time you are either constantly spanking the nuts off it, or there's a problem.

I tried keeping below 2500-3000 rpm on my trips to work, which doesn't include motorways, and managed 30mpg in a 2.8 on Optimax.

And before Spokey, Bloke, etc laugh out loud and call me a liar - yes I really did!

Hope these posts help. Enjoy the forum

Rob

X958 · Post by **X958** » Wed 09 Feb, 2005 09:23

Agree 24mpg is way too low for a 2.0.

The computer thingy on my 3.0 always shows between 27 and 28mpg, that's with a little town driving and twice-daily 90mph+ blasts down the motorway

________
Vapor Genie

Bloke · Post by **Bloke** » Wed 09 Feb, 2005 09:26

RobBruce wrote:

If you're getting 24mpg all the time you are either constantly spanking the nuts off it, or there's a problem.

Rob

And your point is?

Bloke

DavidM · Post by **DavidM** » Wed 09 Feb, 2005 09:40

I dream of 24 mpg

garyw · Post by **garyw** » Wed 09 Feb, 2005 11:37

DavidM wrote:I dream of 24 mpg

but as I said earlier I can get 28mpg on a run, strange eh!!
I did once get it down to 9 mpg on a dawn raid

garyw

ade_g · Post by **ade_g** » Wed 09 Feb, 2005 12:00

my 3.0 is returning 23-24 and that's with my enthusastic use of the high end of the rev band.. in the 1st 4 gears at least

The bmw power fgures for the engines are based on running at 98 ron i think.

Bryn · Post by **Bryn** » Wed 09 Feb, 2005 20:36

DavidM wrote:I dream of 24 mpg

Oh yes indeed!!!

:-)

garyw wrote:I did once get it down to 9 mpg on a dawn raid

I managed 153.7 mile from a full tank on the last "Rutted Toad" day run! I dread to think what it was on the dawn raid!!!!

Russell · Post by **Russell** » Wed 09 Feb, 2005 21:21

With a 2.8 and 95 ron I get around 180-200 miles per tank, before the fuel light comes on.

Based on mileage and not computer, I get between 19mpg (around town) and 25mpg (mainly motorway). I tend to drive at quite high revs, partly habit because I'm still not used to the pulling power the Z has in higher gears, compared to my previous car.

Next time I fill up I'll try Optimax.

Russell

Kenny · Post by **Kenny** » Fri 11 Feb, 2005 10:46

Very little difference between my previous 2.2 & 3.0.. Fuel computer states 22 mpg it's been like that for a while.. most of my driving is in town. Cant wait for the spring..top down cruises Yipee!!!

BlouDonder · Post by **BlouDonder** » Sun 13 Feb, 2005 21:54

Thanks everyone - I read with interest and trying to figure out where my lowly 1.9 fits in. I have had my car for a few weeks now and it is not returning better than 22mpg. I got a real shock after the first tank full when it only did 17mpg (over a few days)! This is all in town. I expected around mid-twenties. I feel like I need to get the car checked out by an impartial technician.

Two comments though.

I wouldn't really trust the trip computer for fuel consumption figures - the bottom line is the amount of miles covered vs how much fuel is required to top up. My previous vehicle's trip computer always overstated its efficiency by about 5mpg when compared to my own calculations.

The second is that "hood on" or "hood off" is likely to make a difference to the fuel efficiency so whether it is up or down should probably always be mentioned when talking fuel efficiency figures.

Vic · Post by **Vic** » Mon 14 Feb, 2005 18:54

Hi, I bought a 99 2.0 a month back and worked out that I got 24.3 mpg with the last fill.

The car only had 11k miles on the clock so I'm not sure if it just simply needs a good run or if there is a problem.
I also noticed that although the temperature gage reaches normal temp fairly quick, the acceleration is still sluggish as if the mix was too rich. It's only after driving for more then 30 minutes that it get's more responsive.

Judging from the different comments, it would appear that 24 mpg is common for many but that the general opinion is that we should get more from the 2.0. Perhaps there is a common problem with the thermostat and auto-choke which is returning a poor mpg for the short runs.

I also noticed that the heater is not always consistent. Some days it's hotter then others.... or maybe it's was just flipping colder this last weekend. !!.

JohnBag - I'd be interested to know if you got your termostat fixed and if it's produced a result.

Or if anybody else have noticed the same.

Cheers...Vic

garyw · Post by **garyw** » Mon 14 Feb, 2005 22:26

Vic wrote:or maybe it's was just flipping colder this last weekend. !!.

Oh Yes it was indeed, we had a mini cooper Cab on demo for the day, as the missus is interested in one, but it was just to damn nut numbingly cold to keep the roof down for too long, it really is quite drafty in them compared to mine or the Zed..
garyw

Grubbins · Post by **Grubbins** » Thu 17 Feb, 2005 08:00

Read this last week and thought I'd check my 2.0 ltr 6cyl. Filled tank, zero'd trip and at next fill up found 26 mpg. Standard unleaded. Car used daily to get to work, mix of open road and 20 mins sat in Nottingham traffic jams (groan). Didn't think it was too bad. Will be taking it for a longer run soon and check that MPG.

JohnBag · Post by **JohnBag** » Thu 17 Feb, 2005 15:21

ahhhhhhhhhhhhh

i drove for a full tank changing gears just after 2000 revs until moterway and then sat at 65mph. result = 29mpg !!!!! wheyyyyy (motorway and normal roads)

2.0 z3 99

what a result!!

lowflyer · Post by **lowflyer** » Thu 17 Feb, 2005 23:47

Well I seem to have opened a can of worms here!!!

Just finished my first tank of optimax and that returned about 26mpg. Not too bad considering I seem to have spent a large part of the last week or so in traffic jams at the Horsham roadworks!! Well I guess I can live with 26mpg since I'm probably only doing about 8K a year (live closeish to work). I guess you guys with the bigger engines have a little more torque and a few less revs at the higher speeds and so are doing a little better than the entry level 6 cyl.

PS May be purely psychological but the engine seems to sound and run a bit better on the optimax.

Grubbins · Post by **Grubbins** » Thu 17 Mar, 2005 11:29

Just to add that I don't reckon much to the computer accuracy - it claims 34.3 - can't be right. Doing the miles and amount put in at the pump give 26.

Paul.Stuhlfelder · Post by **Paul.Stuhlfelder** » Thu 17 Mar, 2005 11:35

I have got no Idea what my MPG is, I just know its time to fill up when the red light comes on... Never been one for MPG myself

Bloke · Post by **Bloke** » Thu 17 Mar, 2005 11:52

lowflyer wrote:
PS May be purely psychological but the engine seems to sound and run a bit better on the optimax.

Dont think it is psychological, Mine definately runs smoother on the stuff

Bloke

LP · Post by LP » Thu 17 Mar, 2005 12:56

I am down to just one light on the service indicator now and the car seems noticeably less powerfull. Am I right in my suspicion that the ECU automatically detunes the car as the service time nears?
LP

Guest · Post by **Guest** » Thu 17 Mar, 2005 16:16

All BMW M52TU engines from September 1998 to April 2000 can suffer from thermostat problems, so your 2 litre is in the 'suspect' group. the usual symptom is a longer warm-up period than usual - several miles rather than 400 metres or so.

Fuel consumption depends a lot on how the car is driven - short cld runs in slow dense traffic will soon pull it down to 22 mpg or so, but lonf runs without drastic prodding of the RH pedal should get at least 30 mpg.

My 2.8 is lucky- it does not get short cold runs, and is driven with a modicum of sympathy - the result is well over 32 mpg per tankful, with (since rechipping, and when wearing the Captain Sensible hat) anything up to 43 mpg while still having a good time! I now regularly get 200-220 miles to the 'half full mark on the fuel gauge, sometimes more.

Mind you - French petrol helps a bit too - the UK has the worst fuel in W Europe. Although the 2.8 is optimised for 98 octane fuel, I have never found any difference in either performance or fuel consumption between 95or 98 octane - and that includes the much-vaunted Optimax!

Advice? Make sure that your brakes are not binding - jack up the car (it's worth finding out how, regardless of your faith in recovery services - I shudder at the thought of an able-bodied man waiting for a little girl in a yellow van to perfom such menial tasks. These days too many people now think that all they need to know is how to work a mobile phone and a credit card!) and try turning the wheels, as the front pads usually corrode to the calipier carriers. Take the calipers off, lever the pads out, and carefully scrpae the rust etc off everything before reassembling with a trace of Copaslip etc on the sliding edges of the pads.

Otherwise, make sure your car is in A1 condition, and drive it with common sense. Remember that most poor fuel consumption problems are due to the driver, even if driving has to be done in dense traffic. To quote Roadcraft (the driving manual of the most skilled nutters in the UK!) 'Mechanical sympathy is a quality to be cultivated in oneself, and admired in others.'

AndyBass · Post by **AndyBass** » Fri 18 Mar, 2005 00:20

Ruddy eck, Mike, 43 mpg out of a 2.8. You must be coasting down some long hills to get that. Like you my 2.8 never does cold start short runs and is in top order and driving carefully I get 32 ish mpg on long runs. Got close to 34 mpg in France last year and I agree that their petrol is better. I used 98 unleaded and the car felt a lot more responsive, but that may have had summat to do with the 900 or so miles it got at high speed clearing it's throat

Guest · Post by **Guest** » Fri 18 Mar, 2005 09:16

Having my 2.8 rechipped made a tremendous improvement to fuel consumption, and making a decent air intake running from the lower mouth to the (standard) air filter also helped a little. I used the local Superchips dealer in Plymouth, the remapping being followed by optimising on a rolling road. I know, some other firms claim to get more out of an engine, but on a normally-aspirated engine you canc only do so much without modification to cylinder heads and cams etc.

As with any car, driving style does help, but like you I used to get about 34 mpg in the same type of driving, so £270 spent on rechipping certianly paid off, not to mention more torque in the mid-range. Even driving on hilly autoroutes (such as the A75 south of Clermont-Ferrand - the best autoroute in the world!) in company with rabid Frenchmen, you have to really try to get the consumption below 32 mpg.

Guest · Post by **Guest** » Mon 28 Mar, 2005 16:51

Like LP, I have found that the number of SI indicators has a profound effect on fuel consumption and performance of my 2.8, as does my daughter, with her 1.9 E36 Compact.

It's all too easy for the manufacturer to link the SI circuit to the engine management system, so - probably - slightly retarding the ignition timing as the number of SI indicators reduces.

This means that after paying £200 to 400 for a posh oil change (sorry - service!) the owner will find that his car is performing better than it was before. This 'Feel Good' factor of course will give the idea that an expensive service is worth having!

We have all heard of M3 owners who tell us that after being serviced by their dealer/specialist, who 'Understands' their engines, it always goes better, so an £850 Inspection 2 is worth paying for! All they are really feeling is the SI being reset!

I do not let mine go past the third SI indicator, as a £15 reset tool is so easy to use. I found that by the time the amber SI light was illuminated the car felt like a real dog, and was amazed by the change after resetting the SI system.

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