BMW Fuel Economy
 

I've got used to outrageous economy claims for the diesel BMWs but had a glance at the average figures for some of the petrol models the other day and was astounded. 40mpg from a 325?!
Absolute figures are meaningless because we all drive differently and I know that Subarus are particularly heavy on fuel but are the BMWs really 10-15mpg better than the rest of the market?
Can anyone who has owned recent petrol BMWs cast any light on whether these differences are backed up by real world driving?

The new 330i around the same power as a 3.0 E36 M3, manages 39.8mpg on average - impressive stuff.

My mates 535d m-sport averages 28mpg over 70k miles, it should do 42mpg.

A chap at work has a BMW 120d M-sport, it should do 58.9 mpg, but he averages 42mpg pressing on across the peaks for 30 miles a day. It does 50 @ 130km/h. With a feather on the pedal I am sure it will hit 60mpg.

So in hilly Yorkshire, during non scientific testing, BMW's average, in real world conditions, 71% of claimed combined mpg. So a 40mpg 325i should do 28.4mpg :)

My 328i gets between 26-30mpg. :thumb:

Does anyone have a direct comparison with other cars?
For example, my wife generally gets pretty close to the "Urban" figure on most cars that she drives because of the type of driving she does. I usually get half way between urban and average figures day to day and half way between average and combined on a long run.
This is pretty consistent whatever cars we drive and at least suggests that the official fuel consumption figures provide a meaningful comparison if not an accurate idea of what actual numbers you will get.

I expect my next car will be a Spec B Legacy which in manual form gives 16/23/32mpg. A 325 is slightly smaller but gives similar performance and 29/39/50mpg. I find it hard to believe that there really will be a 13/16/18mpg difference between these cars.
I still, however, find it strange that the Spec B is about 5mpg more economical with an auto box than a manual - particularly as I know how crap that auto box is!!

Fifth gear did a piece on this

and the conclusion was that the manufacturers claims were pretty much spot on

FiveFWD - Real World Economy video from Fifth Gear

Manufacturers claims are pretty good - only thing is you have to drive like a girl to get them - who really does that....?

Girls?

See VCAcarfueldata.org.uk - Fuel Consumption Testing Scheme for *how they do it*.

"... Urban cycle
The urban test cycle is carried out in a laboratory at an ambient temperature of 20°C to 30°C on a rolling road from a cold start where the engine has not run for several hours. The cycle consists of a series of accelerations, steady speeds, decelerations and idling. Maximum speed is 31 mph (50 km/h), average speed 12 mph (19 km/h) and the distance covered is 2.5 miles (4 km). The cycle is shown as Part One in the diagram below.

Extra-urban cycle
This cycle is conducted immediately following the urban cycle and consists of roughly half steady-speed driving and the remainder accelerations, decelerations, and some idling. Maximum speed is 75 mph (120 km/h), average speed is 39 mph (63 km/h) and the distance covered is 4.3 miles (7 km). The cycle is shown as Part Two in the diagram below. ..."

All on a rolling road which means that it'd be very difficult to replicate, on a *regular* basis, those figures.

Dave

LOL - you know what I mean :p :lol1:

What a scam that sounds like - what about wind resistance etc? :(

I guess it can work both ways. The rollers are dry, and of wet roads have less resistance. I live on the Derbyshire/Yorkshire border and it is very hilly, this also makes a difference.Rollers are ok for an average.

i,m sure the cumputers adjust for all these variables like wind - road resistance etc

as filth gear discovered, the simulated tests figures are very close to real world usage figures

Really :wonder:

I'd have thought wet road would have greater resistance, given the water between the tread blocks.

It is to do with friction - but I guess standing water slows you down!?!?

I've owned cars in the past and achieved what the manufacturer claimed they could achieve but by Christ!! did I have to drive in a way which is so, so mindful of economy, it would drive you nuts after 2 days :D

My view, the figures are all relative but don't assume in the "real world" with a normal "real world right boot" that you will achive anywhere near the mpg quoted. It does seem to be accurate in an "all relative sense" though.............:p

For a few of my recent drives...

I got the manufacturers claimed combined* MPG or slightly more in my Subaru WRX PPP, my old leon Cupra, my old leon cupra diesel, my audi A3 and my wifes Skoda VRs.

For my MBW120d M sport AUTO with 38k on the clock so run in I get 46mpg

I drive all my cars the same on the same work journey each day so the BWM doesn't fare too well for me.

* I probably actually do more motorway than town driving so should get over the combined fig's

got a 125i coupe as a company car, it averages 24.5mpg according to the on board computer. Was brand new when i got it and current mileage is 2.5k so the engine is still running in I guess but not too impressed at the moment.

My 528 sport petrol auto can achieve 40 mpg on a run... I recently got 40.2 mpg on a 140 mile round trip to York..

On the daily commute,stop-start and driving from cold its about 25-26 mpg.

You do need to be mindful of how you drive though..

Now that is meaningful info!
Whether you can achieve the manufacturers figures is irrelevant unless you know what you achieve in other cars.
I know what figures I get in a wide range of cars (relative to the manufacturers figs) but simply don't believe that I will get 35mpg from a 325 while running around locally.
I get the impression that BMW are better at "working the system" than other manufacturers.

My Mrs 330D averages 42-44mpg almost every tank. Never seen under 40mpg