[Milvic]

I find mpg has more to do with being in the right gear. Doing A B roads at 60 and below stay in 5th as 6th is mainly for cruising and you burn a lot trying to accelerate from a higher gear at low speed. while in town doing 30mph 4th seems to strangle 3rd is best keeps the engine at optimum revs easily.
I used to get up to 51mpg when I first got it driving easy since I got back to my normal driving style I get about 48mpg mainly motorway

[djgandy]

Originally Posted by Milvic

I find mpg has more to do with being in the right gear. Doing A B roads at 60 and below stay in 5th as 6th is mainly for cruising and you burn a lot trying to accelerate from a higher gear at low speed. while in town doing 30mph 4th seems to strangle 3rd is best keeps the engine at optimum revs easily.
I used to get up to 51mpg when I first got it driving easy since I got back to my normal driving style I get about 48mpg mainly motorway

It would be great to get engine efficiency graphs rather than the unachievable mpg ratings.

[Milvic]

Originally Posted by djgandy

It would be great to get engine efficiency graphs rather than the unachievable mpg ratings.

48mpg is not unachievable the 318d was far more efficient than my 320d that does 42mpg on the same trip with my driving style. Would be nice to get accurate graph data

[djgandy]

Isn't the 318d rated for 62mpg or something like that though?

[JonnySi]

Originally Posted by djgandy

You cannot get the advertised numbers unless you drive everywhere at ~50mph on a flat road with no wind and never brake.

Considering your journey distance, if you averaged 60mph then you are only driving for 20 minutes. The engine will not be running at full efficiency until the second half of your journey.

~45 seems not too bad. The 320d is probably more fuel efficient than the 320d on A/B road journeys.

Errrrmmmmm well my 325d is only meant to do 47mpg combined, but yesterday at 2 degrees Celsius I drove a 380 mile return trip to Birmingham at 75mph and it returned 54.3mpg, plus I was squeezing the throttle hard on slip roads etc.

[djgandy]

Originally Posted by JonnySi

Errrrmmmmm well my 325d is only meant to do 47mpg combined, but yesterday at 2 degrees Celsius I drove a 380 mile return trip to Birmingham at 75mph and it returned 54.3mpg, plus I was squeezing the throttle hard on slip roads etc.

So you should be comparing to extra urban then which is around 60mpg.

54MPG is a great figure at that speed, but I stand by what I said, barely any cars hit the EU mpg ratings in the real world.

[JonnySi]

It is amazing on fuel, I've driven it very hard around town etc and I cannot get it lower than 44mpg. I totally stand by my initial post that these 4cyl N47's in any guise cannot match a relaxed old school 6cyl. I bet the new 3cyl diesel barely beats the 4cyls in the real world. And my M57 will be more reliable hands down.

[HighlandPete]

Originally Posted by JonnySi

Errrrmmmmm well my 325d is only meant to do 47mpg combined, but yesterday at 2 degrees Celsius I drove a 380 mile return trip to Birmingham at 75mph and it returned 54.3mpg, plus I was squeezing the throttle hard on slip roads etc.

I believe some of it is the way the 325d engine is tuned to develop torque at lower rpm, supports longer gearing, allows for lighter throttle loadings, even at sensible cruising speeds, particularly compared to the 4-pot 2.0d engines.

Would love to see a comparison of the BSFC maps/graphs for the different engines.

For the 318d vs. 325d (autos) there is virtually nothing in it for reported real world averages.

HighlandPete

[HighlandPete]

Originally Posted by djgandy

54MPG is a great figure at that speed, but I stand by what I said, barely any cars hit the EU mpg ratings in the real world.

Agree, and add some motors have no chance in the real world, the setup is just wrong for average driving conditions and speeds. For me a 318d auto fits that group where mpg shortfall will be a bigger percentage than say something like a 325d auto, driven in a similar manner, and at the same cruising speeds.

HighlandPete