Sudden mpg improvement (Blue GT)

[TheFrog]

Just turned 2500km (1500 miles) and fuel consumption has suddenly dropped from 40-42mpg to 50mpg+, at least according to the OBC. And this was driving around town this morning in warm, dry conditions.

Could this just be the engine loosening up? Anyone else had this?

[iichel]

maybe differences in summer/winter fuel?

[lancslad1985]

That's when mine started being eco Frog. I'm now at 5300 miles after 3 months and it's averaging over 50mpg comfortably without trying now it's warm and we are on summer fuel.

[Mart!n-GTI-DK]

Mayby you have just learned/gotten use to drive it properly over the last 2500 miles.

A modern engine is a micrometer perfect piece of engineering and doesn't "losen up".

Mine has had great MPG's since day one because I have driven it as it should to get great milage.

[Doc_House]

I've noticed that mine has improved by about 5-6mpg now getting 61.0mpg on a good motorway run and 50's around town. Very Impressed

[Fedupvw]

Had my Blue Gt for two weeks and can't get less than 50 mpg no matter what I seem to do.

Got 59 mpg coming from work today, very impressed with it indeed.

[Dink]

Remember in warm weather you will see an improvement in mpg as the engine needs to maintain a correct air/fuel ratio.

[Ricmondo]

There is no difference between winter and summer petrol in UK although winter diesel has some anti waxing additives.

I've found my fuel consumption reducing as mileage builds up, theoretically modern engines do not loosen up but in practice there is a significant bedding in process and there are differences in build tolerance, you have only to look at the improved efficiency achieved by blue printing and balancing. I once bought an ex road test fleet car, I won't mention manufacturer to save their blushes but it was significantly faster than other examples and when put on a rolling road it was producing around 10% more power than claimed by manufacturer. When it was later stripped prior to modification the cam profile was standard as were valve sizes but it had been bias bored to ensure that the cylinders were parallel, the Pistons had been machined to even out any weight variance and the flywheel had been lightened to bottom tolerance. Motor was more standard than standard but I think you will see the point I am making.

[tomtoon2015]

In general, newish cars do use less in the summer, my current car (still awaiting polo) has improved since its been a bit warmer, gone from 28MPG upto 32

I think the fuel might be slightly different, also cars are not cold starting/using the heating which saves fuel by not doing so

Strange how some people claim low-high 40's on the BGT, yet some claim low-high 50's/60's...

[Ricmondo]

I no longer obsessively keep fuel consumption records, life is too short but before I cured my self it was noticeable that my fuel consumption was lower when the weather was cold or wet, a function of charge density I believe. That was particularly noticeable on cars using twin of triple Weber DCOE carburettors or early mechanical fuel injection systems.

Winter and summer petroleum is different in many countries that have more extreme climates than.UK but there is no difference at all in UK. The same cannot be said about Guinness, Nigerian Guiness is always stronger than home market brew and that sold in Eire or UK has a lower specific gravity in the summer, a fact that complicates the calculation of excise duty which factors in OG, of course none of that is relevant to the Polo but useful for pub quizzes or if you are a pedantic old fart like me.