Low MPG - 1.2 12V

[Jordanwaterhous]

I have a 1.2 12v too. I also have a ScanGuageII which tells me my momentary mpg, and according to it, the revs doesnt matter its how far you push the accelerator.

Also my ScanGuageII tells me that you use less fuel if you leave the car in 5th when going downhill as opposed to putting it in neutral.
When the car's in neutral it is using fuel to stop it from stalling and to supply power to alternator to power car's electrics.

Whereas if you leave it in gear, the momentum from the energy produced from gravity pulling the car down the hill is enough so the car doesnt need to give fuel to the engine to stop it stalling.
It does however still use fuel to keep electronics working but I find it uses less if left in gear down hills as opposed to putting it in neutral.

Other things i find help save fuel and increase MPG is to have correctly inflated tires according to tire manufacturer rather than SEAT.

Another thing i find helps is to only have 3 gallons on fuel in it maximum. Fuel is heavy and affects fuel consumption quite a bit IMO

Hope this helps!

 

[krussel]

I have a 1.2 12v too. I also have a ScanGuageII which tells me my momentary mpg, and according to it, the revs doesnt matter its how far you push the accelerator.

Also my ScanGuageII tells me that you use less fuel if you leave the car in 5th when going downhill as opposed to putting it in neutral.
When the car's in neutral it is using fuel to stop it from stalling and to supply power to alternator to power car's electrics.

Whereas if you leave it in gear, the momentum from the energy produced from gravity pulling the car down the hill is enough so the car doesnt need to give fuel to the engine to stop it stalling.
It does however still use fuel to keep electronics working but I find it uses less if left in gear down hills as opposed to putting it in neutral.

Other things i find help save fuel and increase MPG is to have correctly inflated tires according to tire manufacturer rather than SEAT.

Another thing i find helps is to only have 3 gallons on fuel in it maximum. Fuel is heavy and affects fuel consumption quite a bit IMO

Hope this helps!

Thats really interesting about cruising down hill, thanks for that

I have a long steady hill on my way home from work and i sometimes play with the mpg readout on the trip in my tdi Fr. When i coast out of gear it freaks and goes 80-90 mpg plus .

The best reading ive got by doing this is 67 mpg on a 8 mile trip which prob relates to just over 50 mpg in the real world.

What you say about the cars electrics needing engine power as opposed to gravity makes sense although ive never really thought about it before.

Going back to mpg of the 1.2, my 1.4 Polo could return 40 mpg if i drove it carefully but the moment you started pushing it along it dropped to 34 ish. I even used to run it around with less that half a tank of gas to help it get going.

 

[superkully]

Most modern cars will stop injecting fuel when you're in gear and have your foot off the throttle. The only time you shouldn't do this is with a manual transmission 2-stroke engine, as the lubrication is in the petrol/oil mix - not that that should apply to anyone on this forum

As has already been said on the forum, get your car serviced. The only time I've gotten around 33MPG was a trip across France, fully loaded and at speed. The other was when the car was making 4-mile trips to work and back.

Now it normally gives 44-45 MPG for a 12-mile commute on A & B roads with some stops in traffic.

BTW the car has done 120,000 miles and is 7.5 years old.

Perhaps also check that the brakes are not binding.

 

[Phantom3110]

I think i'm going to have to get a diesal turbo

My cam chain is being changed out tomorrow and a full service, Hopefully i get a improvement in fuel consumption.....

 

[superkully]

Why are they changing the cam chain?!?

 

[Veyron]

I sometimes wonder if the 12V stands for Volts rather than Valves!

 

[Blanco92]

Why are they changing the cam chain?!?

I believe the chain jumped a tooth or two.

These 1.2s have a tendency to do that from time to time.

 

[ScottHmk4]

i would say stick to gear changed at no more than 2500 revs

 

[Lui]

I believe the chain jumped a tooth or two.

These 1.2s have a tendency to do that from time to time.

I think I read not to change the belt which is £110 but to change the pretensioner(?) which is just £18

Also in 2004 they corrected this 'fault'? Does that mean 04/54 plate onwards is ok or still people have reported slips and needs fixing?

 

[Blanco92]

I think I read not to change the belt which is £110 but to change the pretensioner(?) which is just £18

Also in 2004 they corrected this 'fault'? Does that mean 04/54 plate onwards is ok or still people have reported slips and needs fixing?

You mean the chain.

Yes you can just change the tensioner, as I'm lead to believe the modified parts bought out by SEAT did not feature a modified chain, just a tensioner and a number of guide channels etc. The fact the chains jump from time to time on these engines is due to the tensioner, not the chain itself.

Disregarding the chain itself, I believe the following is what is required to fix the issue if you are to replace the parts as preventative maintenance (i.e. the chain has not already slipped).

- 1x timing chain tensioner
- 1x timing chain tensioner channel
- 1x forward guide channel
- 1x black sump sealant
- 1x timing cover white sealant

Regarding 04/54 reg cars... I don't actually know when SEAT fitted these modified parts as standard.

 

[Deleted member 35176]

On my 1.2 12v, I fill up about 50 quid to the the brim and I get around 400 miles to when the light comes on and I don't really drive economically at all. I use morrisons petrol. On another note does anyone esles 1.2 12v sound a bit tapity??

 

[Jordanwaterhous]

If tapety means whiney then yep mine is too! All of them are! Even with an induction kit mine still whines like h*ll! Exhaust kinda drowns it out nicely though

 

[fandyboy]

Talking about the 1.2 does anyone else experience the "lumpy" engine braking? When I slow down off throttle in 1st or 2nd it is not smooth at all, lumpy is the best way i can describe it. Not noticed it in any other car i have driven.

 

[Deleted member 35176]

you mean jerky?

 

[Blanco92]

Mine is sometimes a bit jerky on the engine breaking, it's not excessive at all, passengers don't notice it, but people who are very picky like me notice it from time to time.

As for tapety, I wouldn't say mine's tapety, it's a bit rattly, but you have to remember it's a 3 cylinder; they're always a bit like that.

I think the above are just a trait of the 1.2s.

 

[fandyboy]

you mean jerky?

Yep, it's quite jerky.

 

[mcculloch]

poor

I have a 55 plate 1.2 12v , £38-£40 fills my tank and im lucky if i get over 200miles out it until the beep comes on, I have a green panel filter installed with small holes in airbox but even from new the car has never gave me anymore than 250miles to tank normal and hard driving, all tyres are checked fortnightly and car is always serviced by seat.

I also run scangauge 2 but my mpg jumps all over the place on it

 

[rocky2008]

im with kidinspace on the shell fuel, i only ever fill up there! 120 to 20pound isnt that good, most i ever got was 210 to 25pound...usually get about 400 to a full tank

 

[stezo2k]

Regarding 04/54 reg cars... I don't actually know when SEAT fitted these modified parts as standard.

I do remember reading the fix was out around 2005 so i'm guessing it got fitted on all the facelifts as standard

 

[Blanco92]

I do remember reading the fix was out around 2005 so i'm guessing it got fitted on all the facelifts as standard

Probably right, it would make sense that the changes happened from facelift onwards.