Help poor MPG

[Double Zero]

Hi

My 2.5 is getting poor mpg, now I didn't buy the car for economy but I've just gone to Birmingham and back, most of the way at 50mph due to restrictions on the motorway, I only averaged 25 mpg.

Car has just been serviced, not showing any codes, I don't believe brakes are dragging, I changed the front caliper that was sticking in April and I replaced the MAF.

Does the new maf need coding in?

If not is there anything else I should be looking at?

Thanks

 

[Smartbear]

Hi

My 2.5 is getting poor mpg, now I didn't buy the car for economy but I've just gone to Birmingham and back, most of the way at 50mph due to restrictions on the motorway, I only averaged 25 mpg.

Car has just been serviced, not showing any codes, I don't believe brakes are dragging, I changed the front caliper that was sticking in April and I replaced the MAF.

Does the new maf need coding in?

If not is there anything else I should be looking at?

Thanks

How are you getting the 25mpg number, are you relying on the trip computer?
Rob

 

[Double Zero]

No worked out manually and using Fuelio app

 

[Double Zero]

When I fill up the OBC reckons I should get 340 miles, afer a 25 mile journey it drops to 270 ish.

 

[Smartbear]

Ok, driving style makes a large difference & if you accelerate hard your mpg is going to suffer-i could get 40mpg from my old 3.0si on a long run.
Was the run you did punctuated by lots of stop/start driving? That will ruin it as well
Rob

 

[Jembo]

Ok...
- was air filter & 3 prong plugs also changed, correctly measuring gaps?
- has oil level been over filled to cause plug fouling?
- what fuel do you use, Vpower / BP or low octane?
- have you tried an Italien tune up (after checking oil level)?
- tyre pressures checked (they need a few extra squirts of air as pressure drops when it’s colder)

 

[R60BBA]

Ok, driving style makes a large difference & if you accelerate hard your mpg is going to suffer-i could get 40mpg from my old 3.0si on a long run.
Was the run you did punctuated by lots of stop/start driving? That will ruin it as well
Rob

40mpg on a run?

I used to get 33mpg tops on my E86 3.0si on runs @70mph using VPower.

 

[Double Zero]

All basics covered tryes pressure set to presures on door shuts.

Running at 50 mph on the motorway, as speed restictions in place, no hard acceleration. I had service done at garage so I assume all plug gaps had been checked and oil levels correct. I've been getting rubbish mpg since I had the car was hoping a service would sort it out, they also checked for vacuum leaks whilst it was in.

I will have to try an Italian tune up.

Thanks for your replies.

I thought I may have read on the forum there was a sensor that could effect mpg but didn't show up as a fault as maybe running just withing tolerance but I have not been able to find the thread.

 

[ph001]

Lambda sensor maybe?

 

[Mr Tidy]

Could be, but wouldn't that throw up a code?

A 2.5 should do much better than 25 mpg on a run like that - my 3.0Si is averaging over 33 mpg (but I'm never out in the rush hour, and it usually does 30+ mile trips on A-roads & motorways).

You mentioned changing a sticking brake caliper - next time you have done a trip it might be worth seeing how hot the brakes are in case you've still got an issue there.

 

[Wood Butcher]

Recently did a 200 mile motorway run. I often use cruise where I can, set @ 70. Averaged 38.6 in my coupe

 

[road warrior]

You may not have had a sticking caliper.. To check for brake issues, Jack each wheel up till clear of the floor and turned it by hand, if there is you will be able to feel it by comparison. You can feel the wheels after a few miles, but a failing flex pipe will release after A few miles of non braking and you will struggle to find the problem while it binds nicely and eats your fuel

 

[Smartbear]

Ok, driving style makes a large difference & if you accelerate hard your mpg is going to suffer-i could get 40mpg from my old 3.0si on a long run.
Was the run you did punctuated by lots of stop/start driving? That will ruin it as well
Rob

40mpg on a run?

I used to get 33mpg tops on my E86 3.0si on runs @70mph using VPower.

Yes

Rob

 

[andyf1140]

A lot of idling in traffic or while warming up wiil reduce tge mpg as well. Also Vanos issues can as well, is it rumming nice and smooth?

 

[mr wilks]

Its winter , if im not mistaken you have a E89 23i auto :? 25mpg aint that far off the scale for that car in real world use .
Id say you are looking for answers to a problem you haven't got i'm currently running a auto N52 Z coupe ( so very similar set up) , doesn't bust 30mpg unless i'm doing 56mph for 30/40 miles & factor in the miles before & after the steady mway speeds it will be around 25/27 showing on readout & average soon drops below that in town .
Suck it up or sell it for a manual 4 pot

 

[Double Zero]

Thanks for the advice roadwarrior I hadn't thought about the flex pipes, might be a good opportunity to upgrade to braided.

Mr Wilks, no its a 2.5 e85, I can never seem to get more than 245 fŕom a full tank.

 

[mr wilks]

Thanks for the advice roadwarrior I hadn't thought about the flex pipes, might be a good opportunity to upgrade to braided.

Mr Wilks, no its a 2.5 e85, I can never seem to get more than 245 fŕom a full tank.

E85 /E86 / E89 , i still don't believe 25mpg average is that bad for a 6 cylinder petrol auto :? i will be doing 450/500 miles next weekend
on a mix of mway & country roads , i'l see what mpg i get brim to brim

 

[patriot66]

Is this an earlier 2.5i with 5 speed gearbox ? :?

 

[philbo909]

Ok, driving style makes a large difference & if you accelerate hard your mpg is going to suffer-i could get 40mpg from my old 3.0si on a long run.
Was the run you did punctuated by lots of stop/start driving? That will ruin it as well
Rob

40mpg on a run?

I used to get 33mpg tops on my E86 3.0si on runs @70mph using VPower.

I also get near 40mpg on a steady run in the Coupe

 

[R60BBA]

Ok, driving style makes a large difference & if you accelerate hard your mpg is going to suffer-i could get 40mpg from my old 3.0si on a long run.
Was the run you did punctuated by lots of stop/start driving? That will ruin it as well
Rob

40mpg on a run?

I used to get 33mpg tops on my E86 3.0si on runs @70mph using VPower.

Yes
6ADA08FD-D100-4FBB-97D7-54D9F9C9BD1A.jpeg
Rob

Your snapshot doesn’t show your mpg fella... :?

Unless you are trying to illustrate you are getting 420 odd miles out of a tank?

What does your trip computer say?