Something Strange Happened Today!

Whilst doing a regular journey to Liverpool today I was keeping an eye on the MPG as this was the first journey on the new 20" wheels and I was curious to see if there was much difference.

I looked at the trip average half way there which would normally read 35+ and it was just under 30!! I started to look at the continuous MPG whilst driving at 30mph in 4th gear, normally it would be anywhere up of 50mpg at that speed and it was going between 20 and 30. I couldnt believe that the larger wheels would make that difference. ANyway I kept an eye on it and after a further mile or so the continual MPG started to return to what it used to, but I don't understand what has happened, very strange.

On the return journey the best I have ever had on that trip driving normally is 40 mpg, today I got 48mpg and at one point it was 52 mpg, so god knows what has happened

I hope this improved mpg continues

Has the rolling cercumference of the wheels changed from what you had on previously?
If so, this will affect the gearing and also affect the calculated fuel consumption as the system will need to know the correct rolling cercumference.

Maybe the DPF regenerating?

(22-09-2012 09:33pm)DiscoDad Wrote:  Has the rolling cercumference of the wheels changed from what you had on previously?
If so, this will affect the gearing and also affect the calculated fuel consumption as the system will need to know the correct rolling cercumference.

It shouldn't have as I have changed from OEM 19" to OEM 20" so should be identical or if not eversoslightly different

Any strong winds down your way today? Travelling one way into the wind really knocks Evoque's mpg, doing the return journey with the wind behind means the car gets an easier drive and burns less fuel.

(22-09-2012 10:30pm)XFullFatTim Wrote:  Any strong winds down your way today? Travelling one way into the wind really knocks Evoque's mpg, doing the return journey with the wind behind means the car gets an easier drive and burns less fuel.

Not at all Tim, lovely still day. It was very strange indeed, to the point I was convinced the garage that changed the wheels hadn't put enough air in and iwas going to check them at the next garage, as it is I thinkntheydo need more air in as they look a bit low when parked up although the 19"s did even with 42psi in! I think he has put them at 36 psi so I will put a bit more in tomorrow.

To be honest my return journey has more up hill so should be worse

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(22-09-2012 09:41pm)SimonS Wrote:  Maybe the DPF regenerating?

I thought the same but wouldn't some kind of warning be shown?

Your DPF would probably have been regenerating there is no indication when it happens, I've seen this on mine its noticeable on the Manual as the start\stop doesn't function, it kills the mpg temporarily as it burning fuel to heat the exhaust.

(22-09-2012 11:39pm)PhilSkill Wrote:  Your DPF would probably have been regenerating there is no indication when it happens, I've seen this on mine its noticeable on the Manual as the start\stop doesn't function, it kills the mpg temporarily as it burning fuel to heat the exhaust.

+1
As for the tyre pressure. You need to set them to the manufacturers recommended pressure. It is illegal (i think) and dangerous to have them incorrectly inflated. Also it causes premature wear

(22-09-2012 10:37pm)THEMACS Wrote:  I think he has put them at 36 psi so I will put a bit more in tomorrow.

36 is correct for the 20's. (front) and 32 for the rears IIRC.

(25-09-2012 01:47pm)RacingSnake Wrote:  36 is correct for the 20's. (front) and 32 for the rears IIRC.

I have 20" Michelins and they are the pressures on the door plate.