New car - does MPG improve over time?
Discussion
Just bought a Polo TDi for the regular commute (I do 18000 miles per year), never had a new car before so wanted some advice. VW post 80+mpg combined which I doubt I will every hit, but I would expect 60-65mpg on a run, early days at the min (<500 miles) but only seeing 45mpg approx...should I expect the engine to loosen over time and the mpg improve, is this normal for a new modern diesel?
Yes. Probably 5-10K miles will see it optimise depending how it's driven.
ETA. Also the first few miles can have a big impact on the overall mpg for a 40-45 miles journey I find. If it's start-stop, then it really screws it in a diesel. Plus it's getting to the time of year that they're going to start to introduce winter diesel at fuel stations. This'll drop the mpg a few as well.
ETA. Also the first few miles can have a big impact on the overall mpg for a 40-45 miles journey I find. If it's start-stop, then it really screws it in a diesel. Plus it's getting to the time of year that they're going to start to introduce winter diesel at fuel stations. This'll drop the mpg a few as well.
Edited by fatboy b on Thursday 4th November 07:31
Doing 18000 miles a year I expect that there's a fair few motorway miles in there? If so the polo won't be the best car for that type of economy. Modern TDi cars obtain their high mpg figures by being run off boost with aggressive curves further up the rev range to still post reasonable acceleration times. If you're cruising around at 80mph you'll be bang in the middle of that curve with a Polo and your economy will suffer.
You'd be as well off with a larger engined diesel if that's the case.
You'd be as well off with a larger engined diesel if that's the case.
jdwoodbury said:
Just bought a Polo TDi for the regular commute (I do 18000 miles per year), never had a new car before so wanted some advice. VW post 80+mpg combined which I doubt I will every hit, but I would expect 60-65mpg on a run, early days at the min (<500 miles) but only seeing 45mpg approx...should I expect the engine to loosen over time and the mpg improve, is this normal for a new modern diesel?
80mpg does seem a wild claim to me, but if its true, then it should be close.Ok an engine will like a few miles on it to fully bed in and loosen up, but not so much so that it is only returning 50% of it's mpg capability.
I'd be tempted to take it back to the dealer and offer them to take you out in it and see what sort of mpg they can achieve with it.
Dog Star said:
I recall hearing that back in the old days Golf GTis gave more power at 100K than they did at new - following this logic I'd expect the fuel economy to improve too.
Older VAG diesels had a nasty habit of being a bit crap at first but improving MPG over time. My sis has been through three VAG sub-2.0 diesels (though NOT the latest gen ones) and seen 30-40MPG at first improve to near 50 or more on the same journey with 10k+ miles on the clock. Oddly one 1.9TDI she had was crap and barely got over 45MPG - weird.
edo said:
fatboy b said:
Plus it's getting to the time of year that they're going to start to introduce winter diesel at fuel stations. This'll drop the mpg a few as well.
I didnt know this - can you elaborate?As a general observation, you seem to get better economy after it has a fair few miles under it's belt. My dads mk1 2 litre diesel passat was doing 52mpg towards the end of it's life @ 120k which was about 7 mpg on average more than when he bought it at circa 40k miles. Likewise his current diesel vectra is pushing 56 mpg currently at 90k miles, when he bought it at 5k miles in 2005 it was doing about 48-50mpg average.
Conversly, my mothers 1.6D C4 is averaging 64mpg at 18k miles. So your polo should be getting much higher mpg than it is doing. Maybe it will start to bed in a little over the next couple of k.
Conversly, my mothers 1.6D C4 is averaging 64mpg at 18k miles. So your polo should be getting much higher mpg than it is doing. Maybe it will start to bed in a little over the next couple of k.
I'm sure what's been said about running in is right. I think there is another effect as well no matter if the car is totally new or not. As you get used to a car, if you are mechanically sympathetic, you will get into driving it in a more attuned way. Basically getting out of it what you need with the minimum effort on your and the car's part. This is a higher mpg driving style and it takes a little getting used to a different car, some you attune to more quickly than others.
a_bread said:
I'm sure what's been said about running in is right. I think there is another effect as well no matter if the car is totally new or not. As you get used to a car, if you are mechanically sympathetic, you will get into driving it in a more attuned way. Basically getting out of it what you need with the minimum effort on your and the car's part. This is a higher mpg driving style and it takes a little getting used to a different car, some you attune to more quickly than others.
Agree completely, it's a combination of both factors.Two things really, which echo what's said above:
1) I know this might sound a bit impertinent of me, but have a look at the way you're driving. Is it a bit too Pistonheads maybe?
For evidence, look at the variation in mpg on the PH real world mpg Wiki! Some people are getting 10 or even 20mpg more than others...
2) The car will improve slightly, but certainly not by 20mpg. If you feel so inclined, I'd have a word with the dealer - perhaps get them to try and achieve 60mpg
1) I know this might sound a bit impertinent of me, but have a look at the way you're driving. Is it a bit too Pistonheads maybe?
For evidence, look at the variation in mpg on the PH real world mpg Wiki! Some people are getting 10 or even 20mpg more than others...2) The car will improve slightly, but certainly not by 20mpg. If you feel so inclined, I'd have a word with the dealer - perhaps get them to try and achieve 60mpg
Edited by RobM77 on Thursday 4th November 12:04
Robm77 you are right, there's a huge variation in driving style. My father piloted my car with 4 adults and lots of luggage and got over 35mpg over a mix of dual carriageways, motorways and undulating A-roads with speeds between 40 and 80. I would have got about 32-33 on the same roads. He does tend to drive more gently when there are women present though which there were!
I also think there is a novelty effect in the early days after changing cars, especially if the car is fairly performance orientated. The early days will involve s lot more exploration of the performance potential of the car - at the least in my experience it does!
I also think there is a novelty effect in the early days after changing cars, especially if the car is fairly performance orientated. The early days will involve s lot more exploration of the performance potential of the car - at the least in my experience it does!
a_bread said:
Robm77 you are right, there's a huge variation in driving style. My father piloted my car with 4 adults and lots of luggage and got over 35mpg over a mix of dual carriageways, motorways and undulating A-roads with speeds between 40 and 80. I would have got about 32-33 on the same roads. He does tend to drive more gently when there are women present though which there were!
I also think there is a novelty effect in the early days after changing cars, especially if the car is fairly performance orientated. The early days will involve s lot more exploration of the performance potential of the car - at the least in my experience it does!
I also think there is a novelty effect in the early days after changing cars, especially if the car is fairly performance orientated. The early days will involve s lot more exploration of the performance potential of the car - at the least in my experience it does!
I've just bought my Dad's car from him and I'm getting more mpg out of it than him, despite driving a hell of a lot quicker. I think it's partly because I don't slow down as much for roundabouts and corners, and therefore don't require acceleration afterwards, because I look a long way ahead and back off in preference to braking (mind you, he does that too), and also because I love driving so much I find it a pleasure to stir the gearbox and often pop up to 6th for a mile or two if up to speed, whereas my Dad probably wouldn't bother. All of that makes a difference to mpg.RobM77 said:
I don't slow down as much for roundabouts and corners, and therefore don't require acceleration afterwards, because I look a long way ahead and back off in preference to braking (mind you, he does that too), and also because I love driving so much I find it a pleasure to stir the gearbox and often pop up to 6th for a mile or two if up to speed, whereas my Dad probably wouldn't bother. All of that makes a difference to mpg.Gassing Station | General Gassing [Archive] | Top of Page | What's New | My Stuff