Golf mk5 1.9tdi fuel consumption

Big_G

I've just bought a Golf mk5 1.9tdi and am getting 7+ l/100km which seems much higher than 4-6 quoted by users and VW (this is from the dash display). I haven't done the tank fill vs. kms driven yet, but this seems high.

I do one trip to and from Dublin per week and then short hops around Limerick four days a week. I do notice in the mornings that the computer throws out massively high figures that seem to die down as the engine warms up. Motorway driving spits out in and around the 7l/100 mark.

Any thoughts? It does need a timing belt and a full service. I've checked tyre pressures and they were low but things have not improved since topping them up. I was thinking of getting a remap done after the timing belt but I'm slightly baffled and slightly disappointed that it doesn't do better than 1.8 petrol 01 Astra that I've switched from. Maybe after service (its 120k roughly) and filters and oil swap gets done it might improve but I'd be expecting it to be just more than half what it is now based on other users posts.

B Rabbit

Big_G wrote: »

I've just bought a Golf mk5 1.9tdi and am getting 7+ l/100km which seems much higher than 4-6 quoted by users and VW (this is from the dash display). I haven't done the tank fill vs. kms driven yet, but this seems high.

I do one trip to and from Dublin per week and then short hops around Limerick four days a week. I do notice in the mornings that the computer throws out massively high figures that seem to die down as the engine warms up. Motorway driving spits out in and around the 7l/100 mark.

Any thoughts? It does need a timing belt and a full service. I've checked tyre pressures and they were low but things have not improved since topping them up. I was thinking of getting a remap done after the timing belt but I'm slightly baffled and slightly disappointed that it doesn't do better than 1.8 petrol 01 Astra that I've switched from. Maybe after service (its 120k roughly) and filters and oil swap gets done it might improve but I'd be expecting it to be just more than half what it is now based on other users posts.

Seems a bit on the low side to me. I know a jetta we had used to manage around the 5l/100km mark

ml100

I have the same car, averaging 5.2 l/100KM, car has 175K km, just replaced the DMF on it, hopefully it will keep going for another few years!

Big_G

Yeah that's what I've been reading in and around the 5 mark with combined driving. Not sure whats going on. Maybe I'll wait to see what she does after a full service and timing belt.

SEAN_DUB

My octavia vrs 2.0 tdi gets less around 6 with 5.5 on motorway miles and my previous mk5 tdi 105bhp offering 4-6 easily

Big_G

Any suggestions? Hopefully the full shakedown at the mechanics will do the job, I'll get him to look at MAF, EGR, check turbo, I do need two new rear tyres aswell, I'll get him to change air and fuel filters and maybe he'll have a few ideas too.

corkgsxr

First give it a full servise then

Check egr, intake blocked or not, maf condition, clean the dpf

Bpmull

I'd start with a full service air oil fuel filter. If the filters are really bad in can effect economy by a good bit. That car should be doing around 5.2-5.8 l/100km around that somewhere. I must check what my dads 2005 1.9tdi octavia is doing it would have the same engine as your golf I think it's doing 5.3l/100km. Another point is do you drive at 120kmh on the motorway. I'm not trying to suggest you are speeding I'm only saying in general anything much over that speed and consumption will dramatically increase as you have air resistance etc. service first before you do anything else.

Bpmull

corkgsxr wrote: »

First give it a full servise then

Check egr, intake blocked or not, maf condition, clean the dpf

I'm fairly sure that engine doesn't have a dpf but maybe if its a 2007 or 2008 it might I'm not sure when they came in but I know my dads octavia doesn't have a dpf and alot of the 1.9tdi didn't have dpfs.

MuppetCheck

Bpmull wrote: »

I'm fairly sure that engine doesn't have a dpf but maybe if its a 2007 or 2008 it might I'm not sure when they came in but I know my dads octavia doesn't have a dpf and alot of the 1.9tdi didn't have dpfs.

1.9tdi never had a dpf. Good reason to buy one like the Focus 1.8tdci.

vectra

What is your driving style like?
Motorway speed?

sebastianlieken

I'd agree with Bpmull here. If it's a new car, I can only asume you plan on keeping it for a while so give it a service for starters. Oil change, air intake filter change, oil filter change. These may very well breath new life into your car in terms of economy and power.

Also, next time you're toping up with fuel, go check the tyre pressures. you're manual will tell you the recommended tire pressures. follow them. I think it's something like 29psi all round for a 1.9tdi.

(the higher the tyre pressure the less rolling resistance - which is great for fuel economy, but the higher the pressure the less grip you'll have for cornering/stopping etc. so follow the guidlines in your manual)

The biggest factor for motorway driving is speed.



You can see from the graph that rolling resistance (tyre resistance) remains constant at any given speed. Drag however, will increase with the square of speed (that's V^2 in the equation below)



So basically, do the oil and filter changes to make sure your engine is running efficiently, and then get those two lines on the graph down as low as possible through proper tyre pressure and economical speeds.

sebastianlieken

also, i'm getting 5.42 l/100km on my 1.6fsi Golf mk5 for motorway driving (120km/hr and 100km/h on the M50)

also, make sure the brakes or hand brake arn't sticking. (take the handbrake off and try push the car, you should be able to shift it and not hear any rubbing or squaeeling)

also, you're not by any chance carrying a load of bricks around in the boot are ya?

godtabh

have you reset the trip computer?

Big_G

Thanks everyone, I drive gently in town, but I do tend to cane it a bit on the motorway. I will do everything suggested. I have not reset trip computer since I got the car. A quick 1km round trip to shops last night revealed nearly 9l/100km. This was done with gentle acceleration and reasonable gear changes. The car does need a thorough going over by mechanic because I've also noticed some vibration at 110-120kmh and sometimes at lower speeds.

I've checked and I think it is wheels or tyres, it happens whether clutch is engaged or not. Just getting a bit worried now because I have terrible luck with second hand cars and I did everything right with this one including having my mechanic inspect it before buying.

sebastianlieken

Big_G wrote: »

Thanks everyone, I drive gently in town, but I do tend to cane it a bit on the motorway. I will do everything suggested. I have not reset trip computer since I got the car. A quick 1km round trip to shops last night revealed nearly 9l/100km. This was done with gentle acceleration and reasonable gear changes. The car does need a thorough going over by mechanic because I've also noticed some vibration at 110-120kmh and sometimes at lower speeds.

I've checked and I think it is wheels or tyres, it happens whether clutch is engaged or not. Just getting a bit worried now because I have terrible luck with second hand cars and I did everything right with this one including having my mechanic inspect it before buying.

a quick 1km trip is nothing to go by. an engine (especially a 1.9tdi) needs to be warm before it starts being efficient. you see the temperature gaugh on the instrument panel? when that's at the half way marker (oil is fully warmed up at 90c) that's when you should be looking at your fuel consumption.

also, the vibration could very well be a wheel bearing. If the bearings are gone it would also explain bad fuel consumption.

but I really stress that fuel consumption cannot be gauged from a cold 1km run.

corkgsxr

sebastianlieken wrote: »

I'd agree with Bpmull here. If i......................nomy and power.

Also, next time you're toping up with fuel, go check the tyre pressures. you're manual will tell you the recommended tire pressures. follow them. I think it's something like 29psi all round for a 1.9tdi.

(the higher the t....................graph down as low as possible through proper tyre pressure and economical speeds.

29 is abit low. 33 minimum for any car

sebastianlieken

corkgsxr wrote: »

29 is abit low. 33 minimum for any car

It depends on the car type (weight), tyre width, tyre type, engine torque etc. it may very well be 33psi, it might be 29, the owners manual will tell you exactly what pressure they should be for the front wheels and the back wheels. (they may be different)

"33 minimum" is a misleading statement though.

EDIT; no need to look in the manual. the tyre pressures are stated on a sticker on the inside of the fuel filler cap.

Big_G

I'm running 32 all round, pressure card on fuel door gives pressures in bar, can't remember off top of my head what they were (2bar maybe?)

Just saw terraclean thread might consider that too if after the service everything ain't kosher.

corkgsxr

id always go 3 or 4 psi higher than manufacturer recommends. they put them to the low side to soak up the bumps better rather than putting better suspension on

robertxxx

Should of got a Honda petrol.