MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: E8RNX on January 12, 2019, 10:30:43 pm

Title: MK5 Golf GTI - Fuel Economy!!
Post by: E8RNX on January 12, 2019, 10:30:43 pm
Hi there guys!

I have a question about fuel economy and (I know there’s many, many threads out there for fuel economy already).

Basically my Golf GTI which I just recently bought has ridiculously low fuel economy - I literally get about 13 MPG average (city driving). From what I’ve read on forums I should be getting about 20’s in city??

I didn’t buy this car for fuel economy at all so I still think every penny is worth it! It’s great fun but the MPG I’m getting is absolutely ridiculous. I also have a VR6 Golf 2.8 which gets much better fuel economy and I’m so confused?!

I know that my MAF sensor is playing up as if I push it in then the engine misfires so I’m about to get that replaced. The fuel economy could be down due to the MAF sensor being faulty from what I’ve heard anyway but it still shouldn’t be this low!

Has anyone had this? This ultra low fuel economy on a golf 2.0 TFSI.

Also to add the car is fully and totally stock, it’s a 55 Plate Axx engine code and nothing has been touched ever, not even a remap.

And finally I use 99 RON only - either 99 Tesco Momentum or VPOWER. Car has also been fully serviced with the cam follower changed too and also little bits like the temperature sensor.

Thanks! Would appreciate what you guys think :)
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: PKGTI on January 14, 2019, 08:32:29 pm
Check the thermostat is working correctly, my car was running cold which meant it was using more fuel, only low to mid 20’s. Since having it replaced my car runs at 90 degrees and I now see late 20’s and up to 34mpg on a run.
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: neilw on January 14, 2019, 09:19:13 pm
Check the thermostat is working correctly, my car was running cold which meant it was using more fuel, only low to mid 20’s. Since having it replaced my car runs at 90 degrees and I now see late 20’s and up to 34mpg on a run.

Yup that's what mine does. I can get up to 40 on a long slow motorway run in light traffic.
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: Octoparrot on January 14, 2019, 09:29:14 pm
Is your low mpg just going by what the trip computer says or have you done your own calculations?
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: E8RNX on January 15, 2019, 08:05:33 am
@PKGTI (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=18782) - I’ll get that checked out - although I think thermostat is fine as temperature goes to 90 quickly within 10+ minutes of driving or so.

@neilw (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=18518) - Wow 40MPG!!!!!! That doesn’t even seem possible to on my car! Right now it’s as if I’m driving a G63 AMG lol.

@Octoparrot (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=14844) - Okay so the 13 MPG figure I quoted is from the trip computer.. The trip computer always shows me stupid MPG figures - Extremely Low.

Calculating the MPG myself after logging miles and how much I filled up I still get around 15MPG maybe and let me add how that’s even sensible driving. When I put my foot down it just eats.


Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: E8RNX on January 15, 2019, 08:09:46 am
Oh and guys let me add. Checking fault codes using a proper Snap-on Diagnostics computer I have found a boost fault code. I don’t believe it’s a leak but something to do with wiring as one of the wiring rooms in the engine bay seems tampered with.

I’m going to check every wire in the engine bay, I’m hoping I find the issue and get better MPG figures! But also full power.
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: muff1991 on January 15, 2019, 11:00:14 am
Start with MAF - either clean or replace that's a big factor.. but as an idea to double check things...

rubbish coils, spark plugs (check gap 100%), dodgy PCV, DV, air vacuum/boost leaks, fuel filter, tyre pressures, tracking and lambda sensors.. amongst an even bigger list, I've seen and heard of all these causing bad MPG.

maybe also run some kind of injector cleaner through it.
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: colesey on January 15, 2019, 11:06:11 am
They are thirsty buggers on short runs - high teens is what we get, with a best of 42 mpg on a long run. All good points to check from the other guys and I would recommend a tank of BG44k also.
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: Dogma on January 15, 2019, 03:14:37 pm
I thought the same after getting my ed30 comparing to my Corrado vr6.

The best I’ve ever got out of a tank is 340miles on a long journey on the ed30, which I thought was pants for a modern car, but it’s fast car so you have to expect it I guess.  Right foot and all that.


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Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: E8RNX on January 15, 2019, 06:32:44 pm
Thanks for all the reply’s guys. It’s so annoying that I can’t post without a moderator checking my comment first lol otherwise I’ve been replying straight after your messages.

Okay update guys: the temperature sensor is fine, my dad actually got it replaced last week and didn’t tell me  :happy2:

@muff1991 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=9978) Thanks for that amazing list.. I will definitely be sure to check all these things and replace. MAF Sensor defo needs changing so that’s first. Like I said earlier for some reason when I plug my current MAF sensor connector in fully the engine starts misfiring. Therefore I’ve left the connector like that too since I’ve bought the car (previous owner left it halfway into the slot too so I didn’t realise).

Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: muff1991 on January 15, 2019, 06:53:02 pm
Thanks for all the reply’s guys. It’s so annoying that I can’t post without a moderator checking my comment first lol otherwise I’ve been replying straight after your messages.

Okay update guys: the temperature sensor is fine, my dad actually got it replaced last week and didn’t tell me  :happy2:

@muff1991 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=9978) Thanks for that amazing list.. I will definitely be sure to check all these things and replace. MAF Sensor defo needs changing so that’s first. Like I said earlier for some reason when I plug my current MAF sensor connector in fully the engine starts misfiring. Therefore I’ve left the connector like that too since I’ve bought the car (previous owner left it halfway into the slot too so I didn’t realise).

No worries at all mate, it’s not a definite answer but it’s a start. 
I would strongly recommend you replace the MAF. If the cars running when you unplug it (running on basic settings) and running rough with its connected then that’s 100% faulty and almost definitely your mpg problem.

Hopefully you’ll be able to skip the moderator bit soon once you’ve done a few posts.

Replace and report back with some better mpg readings :-)


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Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: E8RNX on January 16, 2019, 09:39:55 pm
@muff1991 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=9978)

Update for all you guys!

Just replaced my MAF sensor, engine now doesn’t misfire and getting much much better MPG readings!

MAF sensor was from TPS, I tried one from Europarts as they were giving lifetime warranty too however that didn’t fit.

Thanks for all the help, glad I won’t need to fill up every few days anymore  :laugh:
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: muff1991 on January 16, 2019, 09:44:24 pm
@muff1991 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=9978)

Update for all you guys!

Just replaced my MAF sensor, engine now doesn’t misfire and getting much much better MPG readings!

MAF sensor was from TPS, I tried one from Europarts as they were giving lifetime warranty too however that didn’t fit.

Thanks for all the help, glad I won’t need to fill up every few days anymore  :laugh:
Glad you got it sorted mate, made sense to be the MAF. You are better off with the genuine part for that kind of thing. Much better quality and will provide your ECU with accurate readings. Also will last longer that Euros one.
Enjoy your better mpg. They are not great on fuel, but they do provide pretty good mpg for what they are. Can’t complain, best of both worlds with these cars. Enjoy :-)


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Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: pudding on January 17, 2019, 02:34:14 pm
Faulty sensors aside, this is a classic case of expectations and manufacturers [misleading] claims versus reality  :smiley:

If I drive my ED30 very slowly I can get 400 miles from a tank, which is only 33mpg.  By very slowly, I mean stints of being stuck behind HGV elephant races and never giving it more than 30% throttle, and never exceeding 70mph.  So, by driving a GTI in a very un GTI fashion, it still can't meet the manufacturer's claims.

That's a long term average by the way, verified with pump calculations.

If I drive it how GTIs should be driven, and cruise at 85-90mph where possible, the long term average drops to 28mpg.

To be fair, 28mpg isn't bad for a 300hp turbo hatch.  300hp cars from the 90s would be lucky to return 20mpg.



Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: PKGTI on January 17, 2019, 10:16:48 pm
I think the amount go vs real life fuel consumption is brilliant considering the age of design. I can’t imagine a Mk7 being that much better real world.
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: colesey on January 18, 2019, 05:47:41 am
I think the amount go vs real life fuel consumption is brilliant considering the age of design. I can’t imagine a Mk7 being that much better real world.

Autocar ran a long term test on a mk7 GTi over several months and reported regularly seeing more than 40mpg.
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: pudding on January 18, 2019, 04:31:43 pm
I think the amount go vs real life fuel consumption is brilliant considering the age of design. I can’t imagine a Mk7 being that much better real world.

Autocar ran a long term test on a mk7 GTi over several months and reported regularly seeing more than 40mpg.

Whereas 173 real world people claim 34.8mpg.  VW claim 38 combined.

https://www.honestjohn.co.uk/realmpg/volkswagen/golf-vii-gti-2013

But quite....the performance per gallon isn't bad at all for a 15 year old car.  VAG were early adopters of DI.  It still has it's drawbacks, but it's improved a lot since 2004!
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: colesey on January 18, 2019, 05:07:24 pm
I think the amount go vs real life fuel consumption is brilliant considering the age of design. I can’t imagine a Mk7 being that much better real world.

Autocar ran a long term test on a mk7 GTi over several months and reported regularly seeing more than 40mpg.

Whereas 173 real world people claim 34.8mpg.  VW claim 38 combined.

https://www.honestjohn.co.uk/realmpg/volkswagen/golf-vii-gti-2013

But quite....the performance per gallon isn't bad at all for a 15 year old car.  VAG were early adopters of DI.  It still has it's drawbacks, but it's improved a lot since 2004!

Best go tell autocar that they got it wrong Kev, not me!
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: E8RNX on January 18, 2019, 09:59:32 pm
Yes definitely. They aren’t the best with fuel economy and defo not what the manufacturer figures are. But! The GTI is just so much fun and every penny is so worth it. Mine is just stock right now 200HP and I still haven’t got bored of the power, always beating people off the line when they think it’s a standard Golf.. lol  :happy2:
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: loop on January 20, 2019, 05:26:49 pm
My GT only does around 12mpg in traffic, in first and second gear, stop and start, when cold. But I have got 44 mpg out of it in summer when doing 50-60 mph over prolonged periods!  Recent average is 27-28 mpg.


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Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: PKGTI on January 26, 2019, 04:24:20 pm
Managed 36 MPG on a mixed 30 mile run today.  Considering that the journey included a couple of brief 90mpg plus moments I think that the MPG is really good on theses cars! Worth mentioned I am only running my car on Esso 97 Ron fuel.
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: Chesto18 on January 27, 2019, 01:36:18 am
Might be worth noting, I just changed my fuel filter on a 117k ‘08 plate which I don’t think had ever been changed before and my MPG has shot up from 26-27 ish on medium distance run (20-30mins of stop start and B road cruising) to 32ish MPG.

Car seems to pick up a little better too.
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: rich83 on January 27, 2019, 01:57:27 pm
Mines doing 25.5mpg according to the last 4 fill ups on Fuely.
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: KJNGTi on January 29, 2019, 10:25:24 pm
My thermostat was bad and was getting 30mpg or more... I’ll check it’s average but believe it’s near 32mpg at the moment
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: E8RNX on January 30, 2019, 08:39:48 pm
All you guys get amazing MPG lol. Makes me think what is wrong with my baby 😂😅.
Update on my GTI:

I changed my MAF and MPG improved slightly, not a lot - I felt like the car was obviously running much smoother though.

Next if I didn’t already say on earlier posts I was getting an underboost code (P0299). >> I researched about this and found it to be the diverter valve. I ordered a rev G from Awesome GTI and found that my current one was all torn and ripped in the rubber seals hence the leak.

Now my car is pulling like a plane!!!!!!!!!!!! It is literally rapid, so much so that it just wheelspins constantly - think I need new tyres.

**
After all this my car is pulling exactly how it should and defo getting the right power BUT!! I’m still getting 15MPG :(. And btw that’s not me constantly flooring it, even if I drive nice and calm like an old man in 4th, 5th and 6th gear I’m getting 16 MPG max.

So next I am installing an induction kit (tomorrow) and see if that improves anything. My current standard air box doesn’t have a pipe running all the way to the front of the car like it should so maybe not working efficiently.

If MPG still doesn’t improve then I am going to switch up to R8 coils and new spark plugs which I was going to do anyway and see how she does. Also I’m going to check PCV... there’s no sign to say it’s not working properly but worth a check.

Thanks for all the help guys! I’ll keep you updated.
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: muff1991 on January 31, 2019, 11:13:41 am
I really don't think a cold air intake will improve mpg.. if anything it will make it worse as more airs going in (so MAF etc will introduce more fuel to compensate) not hugely much though.

so when you say 15mpg.. that's what your screen is saying right, have you worked out your exact mpg as in what you actually get from the amount of fuel you have put in?

are you aware of the number 1 and number 2 screens for the cluster (I don't know the exact technical name) but number 2 will display your overall mpg, speed etc and number 1 will be that journeys mpg etc etc. ? if you're not aware about this then its a button under the wiper stalk.. press it once and youll see on the dash top right corner.. 1 or 2 will show.

replacing the PCV is never a bad thing, at least once a new one is in you know that's eliminated. what's your temperature gauge reading.. normal 90?

Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: pudding on January 31, 2019, 01:28:38 pm
If 15mpg was the actual long term average, there would be exhaust soot stuck to the back of the car!

You've changed the MAF and diverter valve.  Give it time to rebuild the mpg calculations.  What does the mpg range say a few minutes after a fill up? 

Agreed with Muff, don't waste money on mods until the engine is running as it should.  The missing snorkel won't cause a ~20mpg loss, but it would be better to have it there to make sure it's not pulling in warm air from the radiator.  You can still get it from VW, it's not much money.
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: E8RNX on January 31, 2019, 09:36:49 pm
@muff1991 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=9978)

Yes I am aware of the both screens. Number one is just the trip and number two is for the past 99 hours of driving or so. With mine you change using the steering wheel!

So yeah on the high line display it’s displaying 13.2 MPG on number 2 and generally for every trip it says around 13-15 MPG.

I have also worked it out using calculations (fuel economy calculator website).... Basically to show you how bad it is I filled a full tank and a week later after about 150 miles the needs was back on reserves and I got about 167 total from the full tank.

Now my car shows no codes at all and no signs of anything like leaks. It is pulling like crazy too!

One thing I can say that I don’t know when has been changed is the fuel filter, I don’t know how big of a difference that can make though as generally petrol is clean as I’ve heard?

Overall I know it’s very very bad as my friend has an edition 30 and he says how he generally gets about 40-50 miles per £10 of fuel. So with the GTI’s 55 litre he gets about 300 miles odd.
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: Chesto18 on January 31, 2019, 09:53:42 pm
@muff1991 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=9978)

Yes I am aware of the both screens. Number one is just the trip and number two is for the past 99 hours of driving or so. With mine you change using the steering wheel!

So yeah on the high line display it’s displaying 13.2 MPG on number 2 and generally for every trip it says around 13-15 MPG.

I have also worked it out using calculations (fuel economy calculator website).... Basically to show you how bad it is I filled a full tank and a week later after about 150 miles the needs was back on reserves and I got about 167 total from the full tank.

Now my car shows no codes at all and no signs of anything like leaks. It is pulling like crazy too!

One thing I can say that I don’t know when has been changed is the fuel filter, I don’t know how big of a difference that can make though as generally petrol is clean as I’ve heard?

Overall I know it’s very very bad as my friend has an edition 30 and he says how he generally gets about 40-50 miles per £10 of fuel. So with the GTI’s 55 litre he gets about 300 miles odd.

Sounds like there is definitely an issue. Take it back to basics. Are your wheels hot after a drive? If a caliper is sticking this will affect performance and MPG.

MAF has been changed and diverter valve. To check PCV pull out dipstick momentarily. If the engine sounds like it’s about to stall, it’s ok.

Fuel filter will improve things if it’s never been changed but not by an extra 15mpg.

Reset the car, disconnect the battery and reset the clocks and go for a drive. See what the new calculations are.

Someone else can advise if there is another sensor that can affect MPG so severely, but my initial thoughts would be MAF which you’ve done.

Are you sure there isn’t a leak? Keep engine running and look under bonnet as well.

How does it start? Injectors would be my next thought after all the above but I’d expect other symptoms.
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: muff1991 on January 31, 2019, 10:27:11 pm
This is becoming a tricky one... we’re running out of ideas haha.

Glad you knew what I meant by the screens, wasn’t teaching you how to suck eggs etc I was just ruling things out yano.

That fueling is definitely messed up tho, you literally are getting half of what you should be really. If you came and said yeah well I floor it everywhere I’d understand, but even to drive like a granny and still get that.. it’s really bad! As @chesto mentioned it could be injectors dumping too much fuel but other symptoms would arise if you ask me. But then you never know with these cars!
Have you got VCDS? Where are you based?
And you say.. other than bad bad mpg, the car drives and idles absolutely perfect?
I wonder if the HPFP is releasing too much fuel or sumin, when was the follower last changed? a fuel filter change may help but again as @chesto said... not enough to warrant you 15mpg back! It’s really a weird one tbh.
I know these cars are not great on fuel, but to say 25+ on a steady granny run is MORE than reasonable if you ask me!
Don’t give up mate, we’ll get to the bottom of it one way or another.
Defo worth jacking up to make sure all wheels are spinning freely tho!


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Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: E8RNX on January 31, 2019, 10:44:22 pm
@Chesto18 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=27005) @muff1991 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=9978)

I’m so happy with all the help I receive of this forum! You guys are so helpful and always there  :happy2: 

Okay so tomorrow I’m gonna get car up and make sure there are no calipers sticking (that could definitely be a big one and one that I haven’t checked). I’ll also disconnect battery just so computers reset, I’m sure this hasn’t been done in a while.

About the PCV, yes when I pull out dipstick it gets super crazy rumbly  messed so I think that seems fine.

And yes defo aren’t any leaks! If I didn’t mention we have our own garage and MOT centre and cover every vehicle! I’ve made sure there definitely aren’t any leaks whatsoever :)

@muff1991 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=9978) I’m based in Sheffield. I’m not familiar with how to use VCDS but know a few people who have it - so I just scan using VCDS? Currently I’ve been using my Snap-on diagnostics the latest one - it gives you live figures too.
Yes fuel is defo so bad right now 😤, hopefully I get to the bottom of it soon enough and will defo keep you guys updated

Once again thank you.
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: akispap on February 01, 2019, 12:12:23 am
I've had almost all the above, I couldn't get more than 31-32mpg on 60-70 in motorways.
It turned out both my rear calipers were dragging me, also I knew my thermostat was gone,
and I had a clean in my inlet and injectors and remap. Now I see easy 37-38mpg on the same speed.
I'm thinking of changing the MAF as well and fuel filter to see if I can get it 40ish!
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: muff1991 on February 04, 2019, 09:37:50 am
@Chesto18 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=27005) @muff1991 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=9978)

I’m so happy with all the help I receive of this forum! You guys are so helpful and always there  :happy2: 

Okay so tomorrow I’m gonna get car up and make sure there are no calipers sticking (that could definitely be a big one and one that I haven’t checked). I’ll also disconnect battery just so computers reset, I’m sure this hasn’t been done in a while.

About the PCV, yes when I pull out dipstick it gets super crazy rumbly  messed so I think that seems fine.

And yes defo aren’t any leaks! If I didn’t mention we have our own garage and MOT centre and cover every vehicle! I’ve made sure there definitely aren’t any leaks whatsoever :)

@muff1991 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=9978) I’m based in Sheffield. I’m not familiar with how to use VCDS but know a few people who have it - so I just scan using VCDS? Currently I’ve been using my Snap-on diagnostics the latest one - it gives you live figures too.
Yes fuel is defo so bad right now 😤, hopefully I get to the bottom of it soon enough and will defo keep you guys updated

Once again thank you.

its nice to see people pull together and throw ideas about the place.. all helps in aid to fix other peoples problems!

I asked if you had VCDS as you could check for misfires etc and also to see where you was based, because if you haven't got it ive just acquired it and would assist If I was closer to you.

did you manage the get the car jacked up and check the rear wheels free spin? (sticking calipers) ?
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: E8RNX on February 04, 2019, 12:04:06 pm
@muff1991 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=9978)

Hope your well. Yes I did jack the car up, no Calipers sticking. To make sure I also got it on brake rollers and came out even, no sticking.

Also checked using VCDS, no suspicious looking faults came out.


Today I have ordered a PCV valve and gasket, will fit it in today and give you an update later tonight hopefully.

Regards :)
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: muff1991 on February 04, 2019, 12:20:14 pm
I'm well thanks. at least you've now ruled out the calipers :)

give PCV a go but I wouldn't hold your hopes up massively on that one as yours sounds ok.

other than what's already been covered, I'm virtually lost for ideas lol

Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: E8RNX on February 04, 2019, 02:25:26 pm
IKR, honestly lol 😳😂

Everything has been ruled out, I couldn’t think what else it could be.

So now I’ve changed the PCV, on the way back home just by looking at trip computer I saw 20 MPG (I have never seen this before lol). I was driving very calmly little to no throttle. Don’t know whether it’s improved yet, guess I’ll have to drive for a while and report back. But saying that even whilst driving calmly on the trip computer I’ve only seen figures max around 15 MPG odd. Don’t know how accurate the computer figures are for you guys but generally speaking after calculating myself they are more or less on point with MPG figures.

I also last week put in a full tank with Fortes Fuel System flush which is meant to be quite good so hopefully injectors should get clean.
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: muff1991 on February 04, 2019, 02:45:07 pm
sounds promising..  :grin: fingers crossed, that could be it.. and if not fully at least its better than what it was!

see how the next tank of fuel goes and go from there :happy2:
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: Chesto18 on February 05, 2019, 01:23:21 am
If it was me I’d now be checking all the fuel line from start to finish. LPFP, filter, HPFP, Injectors, making sure all are working as they should. The fuel is going somewhere!

Are you sure the computer is accurate?

When was your cam follower last changed out of interest?
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: E8RNX on February 05, 2019, 11:30:40 am
@Chesto18 (http://www.mk5golfgti.co.uk/forum/index.php?action=profile;u=27005)

When I get a chance that's a great idea to check all fuel lines thank you. Cam follower was changed about two weeks ago along with service + fuel flush.

Tbh with you since I've changed MAF, DV, PCV i have seen a HUGE improvement of fuel economy without mentioning performance. Im obviously not looking for high fuel economy from a Golf GTI but I definitely want what I'm meant to get at least lol. But yeah I've 100% seen a big improvement.. guess ill just keep driving and see how it goes!

There are some guys on this forum who get MAD MPG figures for a GTI  :laugh:
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: E8RNX on February 05, 2019, 11:34:16 am
Oh yeah and I'm not sure how accurate trip computer is - I don't trust it as it changes figures all the time.

BUT!

The miles remaining on the fuel screen on the highline MFD today as I drove to work was showing 200+ WHICH IS AMAZING  :grin: lol.

Previously, may I add it showed like 120-160 for a full tank haha.

Definitely improved... once I've ran a few full tanks ill calculate what MPG I'm getting and let you know.
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: muff1991 on February 05, 2019, 11:45:47 am
defo an improvement then.. hopefully things get better when the ECU adapts to the new bits and the dash starts showing better figures as time goes on :)
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: E8RNX on February 18, 2019, 01:53:41 am
Hi guys so here’s an update on my fuel economy for the GTI!:

I am getting perfect and the correct fuel economy now, after driving for a while, changing a number of parts it has totally improved from what it was. I went on a long run recently - mostly motorway driving and got 400 miles to the tank!!!!!!!!!!
That was an average of around 30MPG and yeah like I said that was long distance driving - using cruise control on 70MPH then a bit of city too ( and if I say I also floored it a quite a few times too).

Previously what I was getting was ridiculous so here’s what I changed and did from the advice of all the forum members who helped and quite a bit of my own diagnostics using VAG COM and a snap on device. :

- Replaced MAF Sensor
- New DV
- New PCV
- Computer reset by disconnecting battery
- New temperature sensor
- Fuel system flush

So yeah thanks for all the help guys, wish you all the best.
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: muff1991 on February 18, 2019, 02:45:17 pm
really happy its all worked out for you mate and you're now enjoying the car!  :happy2: :congrats:
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: PKGTI on February 18, 2019, 09:13:58 pm
50 mile A road cruise in light traffic yesterday keeping to 70mph I achieved an indicated 39.3 mpg!!

 :happy2:
Title: Re: MK5 Golf GTI - Fuel Economy!!
Post by: Chesto18 on February 18, 2019, 10:03:02 pm
Hi guys so here’s an update on my fuel economy for the GTI!:

I am getting perfect and the correct fuel economy now, after driving for a while, changing a number of parts it has totally improved from what it was. I went on a long run recently - mostly motorway driving and got 400 miles to the tank!!!!!!!!!!
That was an average of around 30MPG and yeah like I said that was long distance driving - using cruise control on 70MPH then a bit of city too ( and if I say I also floored it a quite a few times too).

Previously what I was getting was ridiculous so here’s what I changed and did from the advice of all the forum members who helped and quite a bit of my own diagnostics using VAG COM and a snap on device. :

- Replaced MAF Sensor
- New DV
- New PCV
- Computer reset by disconnecting battery
- New temperature sensor
- Fuel system flush

So yeah thanks for all the help guys, wish you all the best.

Awesome, well done for bottoming it out. So rather than one big issue causing it, it was a combination of parts needing to be renewed. A simple service can work wonders.

I didn’t catch whether you’d changed the air and fuel filter but these are both well worth changing also.