What is the cause for my Low MPG?

[GrahamFR]

Its a new turbo as the old one was totalled, was thinking about giving P-Torque a call and see what he can do for me. But busy atm with work

I might reduce tyre pressure a bit to see what that does, but im sure it wouldnt make much off a difference

reducing tyre pressure will give you more grip but more grip means more work which will mean lower mpg figures

 

[Masterkm]

So could it most likely be the over fuelling thats causing the problem as stated above?

EDIT: Will just got back to me, saying that it would not be an overfuelling issue and he can reduce the map for me but it would be a significant loss in power, so I dont know if I should go with it?

 

[shnazzle]

Could it not just be that your panel filter needs a good clean?
Easily overlooked but definitely affects mpg

 

[Masterkm]

Could it not just be that your panel filter needs a good clean?
Easily overlooked but definitely affects mpg

The panel filter was fitted in August with the new turbo, Im sure that wouldnt be the cause would it esp at 2 months old?

 

[shnazzle]

The panel filter was fitted in August with the new turbo, Im sure that wouldnt be the cause would it esp at 2 months old?

You wouldn't expect so after 2 months....

It does seem like it's over fuelling for some reason, and there are reasons aplenty for that

MAF knacked?
Lambda knacked?
Exhaust leak?
etc etc

 

[Masterkm]

Wouldnt the MAF and Lamda show on VAGCOM, the engine has always come back clean on a scan tbh..

Regards to exhaust leak, wouldnt that be visible? Hmmm at the moment i have my mind set on overfuelling but Will bares to differ :S

Thanks for the constant help you guys are giving though, really want to know whats going on

 

[andycupra]

ANTICIPATION, - cruise is good as many people cant keep a constant speed, however if you know how to drive for good MPG and anticipate you can get better mpg yourself as you can be pro-active rather than re-active which cruise is.

70mph+ is not a great speed for economy. there are some misconseptions regards what drive give better mpg, - motorways are not at great as many would think, an A road is good, if driven correctly.
I get better mpg taking the A1 north than the m1 for example, roundabouts and junctions can increase your mpg if you use them correctly.

Other than this, tips such as slowing IN GEAR, not in neutral, looking ahead, are the lights red amber etc? are they goingn to be red when you get there? then slow down now.. try completing a regular drive without using brakes or stopping.. this will open your eyes to where some gains can be made. (use the brakes if you have too!)


Mechanically, thermostat open or not operating correctly. in appropriate gearing, wheels /tyres such as 18" may not help, it depends on the weight / quality of the alloys, however if heavier then they can act as a flywheel in the case of coasting in gear.. but for most people it will result in a drop in mpg due to how most people drive.

Then of course good servicing and many 100s of things that might not the right in the engine department.

Finally what remap was it? a proper one? not just someone increase diesel rate?

 

[Masterkm]

ANTICIPATION, - cruise is good as many people cant keep a constant speed, however if you know how to drive for good MPG and anticipate you can get better mpg yourself as you can be pro-active rather than re-active which cruise is.

70mph+ is not a great speed for economy. there are some misconseptions regards what drive give better mpg, - motorways are not at great as many would think, an A road is good, if driven correctly.
I get better mpg taking the A1 north than the m1 for example, roundabouts and junctions can increase your mpg if you use them correctly.

Other than this, tips such as slowing IN GEAR, not in neutral, looking ahead, are the lights red amber etc? are they goingn to be red when you get there? then slow down now.. try completing a regular drive without using brakes or stopping.. this will open your eyes to where some gains can be made. (use the brakes if you have too!)


Mechanically, thermostat open or not operating correctly. in appropriate gearing, wheels /tyres such as 18" may not help, it depends on the weight / quality of the alloys, however if heavier then they can act as a flywheel in the case of coasting in gear.. but for most people it will result in a drop in mpg due to how most people drive.

I do alot of anticipation when comes to lights and traffic as I slow down when I know whats ahead.

Will do slowing in Gear though from now on lol.. I only question this MPG issue due to the fact people with PD/CR 2.0l cars are easily doing my figure or maybe better at 70mph etc and wondering how that is possible. I do take care when driving and not like a maniac. I went to the extent of a remap, yearly service, panel filter etc to improve it but nothing.

I know that 18in wheels is a major factor but dont FR's come with 18's anyway?

 

[shnazzle]

Wouldnt the MAF and Lamda show on VAGCOM, the engine has always come back clean on a scan tbh..

Regards to exhaust leak, wouldnt that be visible? Hmmm at the moment i have my mind set on overfuelling but Will bares to differ :S

Thanks for the constant help you guys are giving though, really want to know whats going on

Most of this should indeed show on vagcom...Except for the exhaust leak of course, but then it would be picked up as a fail in exhaust temp or oxygen content picked up by the lambda.

Aren't there margins though? The whole point is of these things is that they tell the ECU to adjust fuelling etc etc based on environment conditions, throttle, etc etc.
If your "leaks" are still within the range that is compensated by the ECU, it might not show on vagcom.

Not 100% sure.

 

[Masterkm]

Might just get it put on the rollers again and see if Will can sort the issue out, I dont mind if the map is reduced slightly if it increases the MPG significantly. Tbh its not like its a race car lol

 

[GlanzaV]

In my PD170 FR I do a 90mi round trip commute every day. by the end of the 45 in trip (maybe 40mi M8 + 5mi town driving) I range anywhere between 49 - 55mpg In all honesty I can put the difference down to speed and driving style. In traffic (when I leave later) sitting between 45-60mph I get the higher end, when I leave earlier and the traffic is lighter I tend to drive a bit faster ~70mph and I'll only achieve maybe 50mpg.

most I've had out was 57.5mpg on the way in one morning when I first got the car and was specifically trying to be frugal.

I also notice on the way home I'll hardly ever manage over 50mpg... whether this is a psychological thing (wanting to get home quicker) or the route changes slightly (traffic at dif points where uphill slowing/acceleration is needed) I'm not sure?

 

[EndlessNameless]

I also notice on the way home I'll hardly ever manage over 50mpg... whether this is a psychological thing (wanting to get home quicker) or the route changes slightly (traffic at dif points where uphill slowing/acceleration is needed) I'm not sure?

I notice that - I have friends about 100 miles away, and when I drive there I get 40-42mpg going there, and ~38 coming back. My house is further above sea level then theirs, but I wouldn't expect that to have to much of an impact over such a distance.

And it's not because I drive faster, I stick the cruise control at 60 both ways, and when I go over there it's usually busier (I come back late at night usually), so more time off the cruise control...

Not that I can add much to the "why is this happening", but it's a peculiar phenomenon.

 

[shnazzle]

I notice that - I have friends about 100 miles away, and when I drive there I get 40-42mpg going there, and ~38 coming back. My house is further above sea level then theirs, but I wouldn't expect that to have to much of an impact over such a distance.

And it's not because I drive faster, I stick the cruise control at 60 both ways, and when I go over there it's usually busier (I come back late at night usually), so more time off the cruise control...

Not that I can add much to the "why is this happening", but it's a peculiar phenomenon.

You get > 35mpg out of a TFSi FR?

I think I did that once...in about 20 miles of traffic going 30-40mph on a B road.

 

[Masterkm]

In my PD170 FR I do a 90mi round trip commute every day. by the end of the 45 in trip (maybe 40mi M8 + 5mi town driving) I range anywhere between 49 - 55mpg In all honesty I can put the difference down to speed and driving style. In traffic (when I leave later) sitting between 45-60mph I get the higher end, when I leave earlier and the traffic is lighter I tend to drive a bit faster ~70mph and I'll only achieve maybe 50mpg.

most I've had out was 57.5mpg on the way in one morning when I first got the car and was specifically trying to be frugal.

I also notice on the way home I'll hardly ever manage over 50mpg... whether this is a psychological thing (wanting to get home quicker) or the route changes slightly (traffic at dif points where uphill slowing/acceleration is needed) I'm not sure?

My point exactly, a car with more power getting better outcome than 1.9TDi, there is something wrong...

 

[EndlessNameless]

You get > 35mpg out of a TFSi FR?

I think I did that once...in about 20 miles of traffic going 30-40mph on a B road.

Only on those long runs with the cruise control replacing my foot. Without those trips I'm more like 25mpg, since my daily commute is all of 4 miles each way, and on the relatively rare occasions where I get it properly warmed up I liked to remind myself what 6000rpm is like.

 

[Deleted member 74601]

Just to let you know a MAF wouldn't necessarily be picked up in Vag Com, in fact, most of them aren't from what I know.

Quick test, unplug it, if the drives like ****, MAF is fine, if car drives better, MAF is farked. You'd notice a drop in power though if it was your MAF.

If you can get your hands on Vag Com, you could monitor the Lambda readings and see if it's overfuelling.