Another MPG topic... Potential reasons why mine is low?

[TimVRS12]

I have similar MPG readings as you were getting prior to your new MAF sensor. Maybe mine needs a clean/ replacing.

Is this the type of stuff I'll need for the clean?:

http://www.ebay.co.uk/itm/85G-BIG-SIZE-TUBE-PERMATEX-DIELECTRIC-TUNE-UP-SILICONE-GREASE-LUBRICANT-3OZ-/250958811254?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item3a6e4f9076#ht_500wt_1204

If not, can anyone point me in the direction of the correct stuff?

[Mike B]

Mind and take your car for the occasional spirited drive, A bit of WOT every now and again to keep things clean & clear.

[softscoop]

Mind and take your car for the occasional spirited drive, A bit of WOT every now and again to keep things clean & clear.

As said.. do this on occasion

[kaitechno]

Ok promised updates so this is what has happened and what I've tried:

- Anti Squeal brake kit - no mpg change

- Sharran Springs incase of handbrake binding - no mpg change

- Upgraded 312mm brakes at the front incase of binding pistons - no mpg change

Now I finally booked it into JKM to get it diagnosed. They came back with(not word for word and from memory) something along the lines of "Plugged laptop in on roadtest, MAF was showing higher levels of airflow. The reason MAF is showing high airflow is due to turbo veins sticking and needing more fuel to push through. The situation will get worse, the car will start in 'limp' mode some days and it will need the car to be turned off and on again and engine management light will show. The only fix is £1100 for a new turbo and fitting. The reason this could have happened because the car has only been driven on short journeys in its life and these turbos are not made for these sorts of journeys."

Obviously hearing this, I was devestated! I bought the car on 25,000 and it's showed low mpg from this time. It's now only on 33,000 and I'd specifically spent more money on getting a low mileage one to avoid any problems.

I did some thinking of what to do next on a miserable drive home and thought about trying to get turbos cheaper, getting a local mechanic to fit or even upgrading to a better turbo etc etc.

The only thing I hadn't tried was the MAF. I thought I had nothing left to lose, so I nipped down to eurocarparts. £116.40 for a reconditioned MAF and 25% briskoda discount put it at £91, and then the return of the old MAF gave £36 off again.

Got it home, changed the MAF over... drove it back to ECP to exhance the old one and........ M'way mpg was showing 65mpg!!!! I was only getting 40 mpg max before the MAF change. Did a little burst around town after, 45-50mpg!! originally was 36-38mpg!!!!!

**Touch wood** at the moment as I've just put in a full tank and will see if I get more than the 360miles I was getting before the MAF change.

I'm not having a go at JKM because I do find their service top notch, and the sticking veins may still be an issue but I've seen no loss in power from the turbo whatsoever and my main issue was the MPG. The new MAF appears to have fixed that. I will update again when I've gone through this tank.

I've had my vrs for 2 years now and suspected my fuel consumption was a bit low. I had it checked out when I fisrt got it and then had it checked again today(laptop plugged in on a drive) by my local garage today and they said there was no fault with the MAF or temp sensor, although they did say the turbo was overboosting a little bit.

Did you notice any difference in power before and after fitting the new MAF? Also, did you notice if it was smoking a lot before the changeover?

I'm thinking about changing mine just for peace of mind, coz it's always niggled me that there might be something not quite right.

[sjparker]

I've had my vrs for 2 years now and suspected my fuel consumption was a bit low. I had it checked out when I fisrt got it and then had it checked again today(laptop plugged in on a drive) by my local garage today and they said there was no fault with the MAF or temp sensor, although they did say the turbo was overboosting a little bit.

Did you notice any difference in power before and after fitting the new MAF? Also, did you notice if it was smoking a lot before the changeover?

I'm thinking about changing mine just for peace of mind, coz it's always niggled me that there might be something not quite right.

Yeah, as someone said before the MAFs can fail without throwing any fault codes on diagnostics.

There has been no difference in performance or power, just much higher mpg

At the end of the day, 25% briskoda discount and £36 refund for the surcharge brings it to about £64. So it's worth a shot.

There a few reasons why mpg could be low, the main ones seem to be brakes rubbing in some form, air filter or MAF.

[stueygonzales]

Probably an incredibly stupid question but then im not mechanic so not that stupid.

What is a MAF??

[sjparker]

Probably an incredibly stupid question but then im not mechanic so not that stupid.

What is a MAF??

Mass Air Flow (MAF) sensor

[sjparker]

And for anyone interested the Bosch MAF part number is 434440680

[stueygonzales]

Nice, thanks!

Thinking of giving it a clean if such a thing is possible to possibly improve the MPG.

[kaitechno]

I went to TPS to get a price for a new MAF sensor and they gave me a price for an 'air mass meter'. Does anyone know if this is the same thing, only the whole unit rather than just the sensor by itself? On the diagram it seemed to have the sensor and the whole tube housing. The price was £85 which seemed about right.

[Jasons]

I went to TPS to get a price for a new MAF sensor and they gave me a price for an 'air mass meter'. Does anyone know if this is the same thing, only the whole unit rather than just the sensor by itself? On the diagram it seemed to have the sensor and the whole tube housing. The price was £85 which seemed about right.

sounds about right,on the eurocar parts website it shows a picture which is the whole thing,the price sounds about right as well.but if you order online and use the briskoda discount code and the with the surcharge off as well it brings the price to about £65.and it is a bosch one,i am tempted to get one for my vrs as not entirely happy with mpg.

[BRUN]

im averaging 45mpg and ive always wondered whether changing my MAF might boost it up a bit, never brought myself to part with the ~£70 though with no warning light on

[piggoy]

Ok promised updates so this is what has happened and what I've tried:

- Anti Squeal brake kit - no mpg change

- Sharran Springs incase of handbrake binding - no mpg change

- Upgraded 312mm brakes at the front incase of binding pistons - no mpg change

Now I finally booked it into JKM to get it diagnosed. They came back with(not word for word and from memory) something along the lines of "Plugged laptop in on roadtest, MAF was showing higher levels of airflow. The reason MAF is showing high airflow is due to turbo veins sticking and needing more fuel to push through. The situation will get worse, the car will start in 'limp' mode some days and it will need the car to be turned off and on again and engine management light will show. The only fix is £1100 for a new turbo and fitting. The reason this could have happened because the car has only been driven on short journeys in its life and these turbos are not made for these sorts of journeys."

Obviously hearing this, I was devestated! I bought the car on 25,000 and it's showed low mpg from this time. It's now only on 33,000 and I'd specifically spent more money on getting a low mileage one to avoid any problems.

I did some thinking of what to do next on a miserable drive home and thought about trying to get turbos cheaper, getting a local mechanic to fit or even upgrading to a better turbo etc etc.

The only thing I hadn't tried was the MAF. I thought I had nothing left to lose, so I nipped down to eurocarparts. £116.40 for a reconditioned MAF and 25% briskoda discount put it at £91, and then the return of the old MAF gave £36 off again.

Got it home, changed the MAF over... drove it back to ECP to exhance the old one and........ M'way mpg was showing 65mpg!!!! I was only getting 40 mpg max before the MAF change. Did a little burst around town after, 45-50mpg!! originally was 36-38mpg!!!!!

**Touch wood** at the moment as I've just put in a full tank and will see if I get more than the 360miles I was getting before the MAF change.

I'm not having a go at JKM because I do find their service top notch, and the sticking veins may still be an issue but I've seen no loss in power from the turbo whatsoever and my main issue was the MPG. The new MAF appears to have fixed that. I will update again when I've gone through this tank.

@sjparker - Are these MPG figures as indicated on your trip computer or are they properly calculated using the 'brim to brim' method? My trip computer seems to over estimate MPG by about 20%.