57mpg to 32mpg

[chrispy.]

Hi

When I got my car second hand from Huddersfield VW, on way home i was doing 80mph down the A12 getting 57mpg. Now if i do 80mph, i get 32mpg
Would this be because it needs a service? Or is there something else?

[rover220]

I wouldnt rely on the dash readout. Not accurate in the slightest.

[john.p.clegg]

I just hope plod is not reading this....sounds like a confession...

John

[alexperkins]

What engine? The tdis suffer from egr issues causing low mpg

[chrispy.]

I have the 1.2 TSI
Also, ive gone from £25 = 250 miles to £25 = 200 miles.

Just wondering if its because its due a service?

[AJ_7]

Have you recently had new tyres fitted?

[chrispy.]

Nope same tyres since i got the car in May 2013.

[Mart!n-GTI-DK]

It's not uncommon that the mpg's drop when it's cold...

[vc-10]

Check the tyre pressures too. If they're low it causes more resistance as the tyre deforms more. Not good for the tyre either!

[chrispy.]

Hmm ill have a look. Thanks for the answers guys!

[john.p.clegg]

Martin
"It's not uncommon that the mpg's drop when it's cold..."after the disaster of my wishbone bushes, my MPG reduced from 40 to 35 and I thought proper bushes/new tyres and tracking would sort it,but,the last tankful still gave 35 mpg....now my understanding of it is that the Lambda sensor gives info to the engine management unit to correct the air/fuel mixture..the air when colder is denser so one needs more fuel..but no extra power is needed if driven the same way,so less throttle... so why "It's not uncommon that the mpg's drop when it's cold..."

Thanks
John

[rover220]

Martin
"It's not uncommon that the mpg's drop when it's cold..."after the disaster of my wishbone bushes, my MPG reduced from 40 to 35 and I thought proper bushes/new tyres and tracking would sort it,but,the last tankful still gave 35 mpg....now my understanding of it is that the Lambda sensor gives info to the engine management unit to correct the air/fuel mixture..the air when colder is denser so one needs more fuel..but no extra power is needed if driven the same way,so less throttle... so why "It's not uncommon that the mpg's drop when it's cold..."

Thanks
John

engines take much longer to get to their most efficient

[RUM4MO]

engines take much longer to get to their most efficient

Exactly, if anyone is brave/stupid enough, try switching the fan or A/C off a cold morning until you think the car engine is warm/hot - maybe two miles, then switch fan or A/C back on, at the end of that journey you should expect a substantial improvement in that journey's MPG over same journey/conditions with the fan or A/C running from engine start. I live up North and I've been doing that while using my daughter's 6J Ibiza - just to boast about the MPG that I can get on my commute to work.