Very poor mpg at 21.5 mpg

[chrisdc]

Thanks Sony,

All true and correct no doubt. My car is 4 and half years old. In S.A. they were sold with a 5 year 100,000km maintenance plan. I've only had the car a month or so and its on about 97,000km as i write. If there are problems, i'd like to get them sorted before this plan expires.

As previously mentioned, this car has a full service history at Volvo. Judging by the condition of the car it was very well looked after by its previous owner. Its been doing about 20,000km a year - too much for just short runs to the shops and back, me thinks. So it must have seen some open motorway - but i'm just speculating. It has new tyres of the correct size and no add-ons apart from the standard roof rails - and no tow hitch.

A look under the car shows a weight on the rear axle but no EOLYES tank. 8th digit in the Vin is a 5. So it would appear to be the same system as Zeb246 has. It's also a Powershift - reading the forums, it would appear that these got the "everlasting" DPF when the manual equivalent model did not. (year and series)

I'm hoping that what worked for Zeb will work for me too. Thing is we have cameras everywhere and also average speed prosecution, so how do i do an extended trip at the speeds Zeb did? Our max speed is 120km/h and thats about 2000rpm on a Powershift. Should i manually override the transmission and do it in 5th or 4th?

Someone mentioned that sometimes garages are able to "regenerate" DPFs on site. Is this done with a blowtorch or by revving the engine on a stationary car? Any guidelines for this - how many rpm and for how long?

Thanks to all who have contributed so far. I hope to post a "success photo" like Zebs in the not too distant future.

[chrisdc]

Hi SonyVaio,

Haven't figured out how to insert a partial quote yet but you wrote the following:

Tyres: both tyre pressures and type of tyres themself can have an impact on MPG. A drop of only a few PSI can see a reduction of 3 or MPG on its own. Then there is tyre quality, look at the wear rate and energy efficiency of your current tyres. Often cheap (and sometimes expensive) tyres can have a hefty efficiency rating thus costing you in MPG.

"EGR: If you have a faulty EGR this can have an effect on MPG

FPS: Fuel Pressure Sensor - if this is faulty or on its way out it can cause havoc with MPG

MAF: Mass Airflow Meter - used to measure air quantity into the engine so the ECU can work out air/fuel mixture, if this is faulty then this will/can drastically reduce MPG.

Brakes: If you have sticking brake callipers then this of course can be very lightly braking the car constantly thus causing a rise in MPG

Injectors: faulty injectors can increase MPG"



These items all sound expensive.... if any of the above were faulty or on their way out, wouldn't the OBC know about this? (logged error code)

Ok, sticking callipers won't generate a code but this type of problem usually occurs on older cars that have not been serviced properly (regular brake fluid changes). Correct?

Tyres are Dunlop 6060 series. I'm not a Dunlop fan, preferring Michelin myself, but they had just been fitted a few days before i got the car - so couldn't refuse them. Have inflated as per owners manual.

I had to strip and clean the EGR valve on my Renault van - lots of black smoke, but it doesn't have a DPF so i was able to see the smoke. Woiuld you know if cleaning of EGR is part of standard Volvo service procedure?

I'm worried that as my car is so close to the end of its Maintenance
Plan, Volvo might choose to "ignore" any potentially expensive problems (especially if they are not obvious failures) in an attempt to buy some time and save themselves some money. I feel a bit bad saying this of them - they've had to do a transmission repair recently (just before i bought the car) and they're about to replace a faulty deadlock on a rear door so my experience so far has only been good..... still reading the forums, lots of people have not been so lucky. (It took more than a month to get the transmission fault authorised and repaired bythe way) The car was "in-between owners" at the time but still.... its a long time to be without a car if its your only transport.

[SonyVaio]

Originally Posted by chrisdc

These items all sound expensive.... if any of the above were faulty or on their way out, wouldn't the OBC know about this? (logged error code)

Not necessarily, it is even possible to get codes but not get the management light as well.

Ok, sticking callipers won't generate a code but this type of problem usually occurs on older cars that have not been serviced properly (regular brake fluid changes). Correct?

You can get almost brand new cars that develop sticking callipers, there is instances of people on here with nearly new cars and even less than 1yr old that have had to have replacements.

Tyres are Dunlop 6060 series. I'm not a Dunlop fan, preferring Michelin myself, but they had just been fitted a few days before i got the car - so couldn't refuse them. Have inflated as per owners manual.

You may want increase the pressure slightly by about 3 or 4 PSI above standard or onto the pressure settings if the car was fully laden - you should find this will increase MPG slightly. This is also known as ECO settings.

I had to strip and clean the EGR valve on my Renault van - lots of black smoke, but it doesn't have a DPF so i was able to see the smoke. Woiuld you know if cleaning of EGR is part of standard Volvo service procedure?

Cleaning of the EGR is not a standard Volvo Service proceedure. Volvo woyuld be more interested in just replacing an EGR. It is a very simple job and there is guides on here to follow so definitely one you can do yourself if required.

I'm worried that as my car is so close to the end of its Maintenance
Plan, Volvo might choose to "ignore" any potentially expensive problems (especially if they are not obvious failures) in an attempt to buy some time and save themselves some money.

Unfortunately if there is nothing detected and also no codes after a check then as you say Volvo are not going to be interested in any in depth diagnostics to find your MPG loss, especially if it is going to cost them. Unfortunately you are going to have to do the leg work and thedn if you find anything wrong then you can get Volvo to sort it whilst you are still under warranty.

I feel a bit bad saying this of them - they've had to do a transmission repair recently (just before i bought the car) and they're about to replace a faulty deadlock on a rear door so my experience so far has only been good..... still reading the forums, lots of people have not been so lucky. (It took more than a month to get the transmission fault authorised and repaired bythe way) The car was "in-between owners" at the time but still.... its a long time to be without a car if its your only transport.

All I can say on this one is; do they not supply a courtesy car whilst yours is in for a repair? The other thing is, as long as you have taken the car to the dealer and ANY fault has been identified and 'Loged on Volvo System' along with all the information required to prove at that point in time it is still under warranty (as you are now very close to being out of warranty) then even if Volvo cannot fix it therer and then they will (or should ) honour the warranty if had to take the car back a couple of weeks later to be fixed but in reality may now be 100km outside the warranty?

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[chrisdc]

Originally Posted by Zeb246

Thanks, well impressed with the mpg only slight problem though. I did 75 miles of journey and the mpg was 35.7, by the time I got to around 100 miles it went up to 40 mpg. It took bloody ages to get it at that mpg but I somehow managed to keep it up in the highs.

I filled her up with Shell normal diesel, not the special diesel. Though I may fill 15 litres of V-Power.

So many people contribute to these forums so it's difficult to know where to start when thanks are due but this particular post got me thinking.

Well, i've just come back from a 260 odd Km drive in the country (a totally nerver wracking experience under the circumstances) and TA-DA!! 5.2l/100km (it flipped over from the 5.1 in the photo while i was taking a shot of the outside of the car). 45mpg !! (28.5mpg before i left)

A VERY BIG thank you to everyone for contributing and for all / and to all the people that make these forums possible.

More to follow....

[SonyVaio]

Do you reset the info centre at all?

In your picture you are on T2 which means Trip 2 and of cource it counts up the miles since the last 'Trip' was reset. You also have a T1 which counts up mileage too. So you could for example: With T1 only reset that when you do fill upsa and then know how far you've gone between fill ups whilst still being able to use T2 to say measure the distance from A to B.

Also in your picture you are now obtaining 5.1l /100km as your Average Economy - but over how far a distance?? If you reset T1 or T2 it has NO effect on the calculated distance in terms of measuring Average Economy. For example the person that had the car before you may have driven like a nutter and only got a true 20 MPG but you drive like a saint and get a true 40 MPG, it will depend on the last time the 'Info Centre' was reset to start giving more acurate readings of your own. The computer may have known about 10,000miles of 20 MPG and then you come along and drive at 40 MPG but it will take a very very long time/mileage for the computer 'Average' to rise. If you do a 'Info Centre Reset' this would wipe out the 10,000 miles at 20 MPG (in this example) and then it would start calculating on your driving from when you reset it.

In summary, 'Average Economy' is done via a calculation over all the driving the car has done since the last 'Info Centre Reset' and if a lot of harsh driving has been done in that period then it will take a long time for economy figures to rise. The best option is to reset the 'Info Centre' and then let it start calculating from new on your driving.

How To Reset Info Centre: Look at your left hand stalk and half way down the stalk you will see a button that has 'Reset' on it. Navigate your screen to read the current average economy and if you press and hold the 'Reset' button, after 2 seconds it will say something like 'Economy Reset', you COULD release the but now and the Average Economy will indeed be reset and if you were to scroll through the computer you would find the other settings still as they were (Average Speed, etc...). What your best off doing though is instead of just holding the 'Reset' button for 2 seconds hold the button for 4 or 5 seconds and the display will say something like 'Info Centre Reset'. Now just press the 'Read' button at the end of the stalk to get rid of the Reset message. This will have reset ALL setting like 'Average Speed' with the exception of not resetting T1/T2 mileage.

[chrisdc]

Originally Posted by SonyVaio

Do you reset the info centre at all?

In your picture you are on T2 which means Trip 2 and of cource it counts up the miles since the last 'Trip' was reset. You also have a T1 which counts up mileage too. So you could for example: With T1 only reset that when you do fill upsa and then know how far you've gone between fill ups whilst still being able to use T2 to say measure the distance from A to B.

Also in your picture you are now obtaining 5.1l /100km as your Average Economy - but over how far a distance?? If you reset T1 or T2 it has NO effect on the calculated distance in terms of measuring Average Economy. For example the person that had the car before you may have driven like a nutter and only got a true 20 MPG but you drive like a saint and get a true 40 MPG, it will depend on the last time the 'Info Centre' was reset to start giving more acurate readings of your own. The computer may have known about 10,000miles of 20 MPG and then you come along and drive at 40 MPG but it will take a very very long time/mileage for the computer 'Average' to rise. If you do a 'Info Centre Reset' this would wipe out the 10,000 miles at 20 MPG (in this example) and then it would start calculating on your driving from when you reset it.

In summary, 'Average Economy' is done via a calculation over all the driving the car has done since the last 'Info Centre Reset' and if a lot of harsh driving has been done in that period then it will take a long time for economy figures to rise. The best option is to reset the 'Info Centre' and then let it start calculating from new on your driving.

How To Reset Info Centre: Look at your left hand stalk and half way down the stalk you will see a button that has 'Reset' on it. Navigate your screen to read the current average economy and if you press and hold the 'Reset' button, after 2 seconds it will say something like 'Economy Reset', you COULD release the but now and the Average Economy will indeed be reset and if you were to scroll through the computer you would find the other settings still as they were (Average Speed, etc...). What your best off doing though is instead of just holding the 'Reset' button for 2 seconds hold the button for 4 or 5 seconds and the display will say something like 'Info Centre Reset'. Now just press the 'Read' button at the end of the stalk to get rid of the Reset message. This will have reset ALL setting like 'Average Speed' with the exception of not resetting T1/T2 mileage.

Good morning all,

Hi SonyVaio,

Sorry couldn't write more yesterday - had a dinner engagement and had to prepare for that. Was just so excited by the results I wanted to post something! But you're right the exercise could have been a bit more scientific. And you are right of course about the counters, reset etc. But let me explain...

Ok,

1) I did not fill up the car before I left. I only reset the trip counter when I fill up because I have an inherent distrust of fuel gages, and as already mentioned elsewhere, I like to work out my fuel consumption the old fashioned way - fill tank and divide km travelled since last reset by litres needed to refill. This method is absolutely bullet proof and only takes into account the driving style used to empty the last tank. This is also how I obtained my previously posted figures, 11.7 and 11,3 km/l. (8.54 l/100 & 8.84 l/100)
2) Its on T2 because I couldn't find a pen last time I filled up. So I reset T2 and subtracted T2 from T1 when I got home. The litres needed are printed on the cash slip. (this was to give me the figures for the last fill - nothing to do with this trip at all)
3) This trip was not meant to be a "scientific" experiment and I did not note the km already travelled since the last fill when we left. We think T2 was on about 160 odd km when we left. We estimated the trip to be at least 120km either way, possibly 140km.
4) I did however reset the OBC info centre (average speed & average L/100) before we started our return trip. I got the "Soot particle filter full" message as we were leaving home - good timing for a change because I’ve had it appear at the end of a long trip - which is not helpful at all) I figured that the regen would have had a chance to complete on the way up so safe to reset and see what my baby can really do. So, only the return part of the trip was monitored in a reasonably "accurate and scientific" way.
5) The 5.1 l/100 was obtained over a distance of about 120 / 140km. We drove home at the legal limit (100km/h & 120km/h - mostly the latter) stopping at a nursery to buy some plants and planters. The bit from the halfway point to the nursery was done at a very leisurely 60km/h meandering through some twisty country roads. The trip home also includes some long steep hills and I was not trying to drive particularly economically, I like to "floor it" on the hills where the torque of the diesel really comes into its own.

The "regen" process:

This is the part that mystifies me because in the very short time I’ve had the car (I’m still on my third tank of fuel) I’ve had 3 "Soot particle filter full" messages and presumably undergone 3 regen cycles. We were trying to drive with economy in mind which I’m beginning to think is a mistake with a DPF equipped car. This is borne out by the worsening fuel consumption 11.7km/l first tank, 11.3km/l second tank. (After this last documented trip its up tp 19.23km/l ! )

So what did I do differently?

Put the automatic Powershift transmission in manual mode and forced the transmission to stay in 5th and 4th gears and trying to keep the revs in the 3000 / 3800 rpm bracket - especially on the hills. That’s it!

Because of all the cameras and as mentioned, we have average speed prosecution as well, I couldn't do it Zeb246s way (driving faster) and this seemed to me the only alternative.

Will write more later – duty calls, I see Her Ladyship has finnaly woken up, got to go and make coffee

[Zeb246]

Sooo... My mpg has gone down to 20 mpg, it's been 3 weeks since the mpg has decreased. I must of got lucky by bringing the mpg up to 40, when I took her up to London 200 odd miles there and back.

I've booked my car in for the 'free health check' so will inform Volvo about the dreaded mpg, and hope they can find a solution.

[danielg1980]

I think it was earlier in this thread or another one about mpg somebody mentioned tyre pressures, I had a look at mine when I was filling up today. I was quite shocked to find that all 4 were down to 29psi! The sticker on the drivers door pillar was a little difficult to make out so I went for 35psi all round. I have a nice long drive to the west country next week so will hopefully be able to notice a difference, just driving back from the petrol station it felt a nicer to drive.

On an unrelated note I've a attached a pic of the car after I gave it a coat of autoglym super resin polish and a top coat of autoglym extra gloss protection. Looking good in the sun.

[Zeb246]

Originally Posted by danielg1980

I think it was earlier in this thread or another one about mpg somebody mentioned tyre pressures, I had a look at mine when I was filling up today. I was quite shocked to find that all 4 were down to 29psi! The sticker on the drivers door pillar was a little difficult to make out so I went for 35psi all round. I have a nice long drive to the west country next week so will hopefully be able to notice a difference, just driving back from the petrol station it felt a nicer to drive.

On an unrelated note I've a attached a pic of the car after I gave it a coat of autoglym super resin polish and a top coat of autoglym extra gloss protection. Looking good in the sun.

I pumped up all 4 tyres to 35psi, but still no luck. Would changing the oil and oil filter help the mpg go back up again? I couldn't seem to find the fuel filter underneath the car. Where exactly is the fuel filter located?

Car look's squeaky clean with the autoglym polish. I think it's time to polish up my car soon with the 3 stage Meguiars polish.

[Darlo 1]

Originally Posted by Zeb246

Sooo... My mpg has gone down to 20 mpg, it's been 3 weeks since the mpg has decreased. I must of got lucky by bringing the mpg up to 40, when I took her up to London 200 odd miles there and back.

I've booked my car in for the 'free health check' so will inform Volvo about the dreaded mpg, and hope they can find a solution.

Bet its cos you keep rubbing kerbstones