Reduced MPG after a trip to the stealers!

[jay.ing]

Just had my first motorway run after i got my car back from the stealers, my mpg has dropped from about 55 to 40? it was in for some handling issues and a vibration when breaking, the tracking has been adjusted, ive new discs on the front and the wheels have been moved around the car! Has anyone got any ideas why this is?

The journey was 200 miles, i was sitting around 70 and i was barly getting 42 mpg, so then i got bored and sat at faster speed (Shh!) say 15 more ish! and was getting 33-34mpg?

 

[pow]

I am having similar sort of troubles, but compaired to my old Ibiza, my currnet one is slightly lower (3-4mpg lower - and im driving them the same). The only difference between the two is:

-New one has PD160 intake
-New one has poly brushes
-New one has different tyres (IE. the more "racing ones")
-New one has an aftermarket stereo

Any ideas for us?

 

[kriso]

tyre pressures or new brakes rubbing slightly while they bed in?

 

[T. Spark]

tyre pressures or new brakes rubbing slightly while they bed in?

Guess is as good as any.

If doing lots of motorway miles always best to throw up the PSI a little on all four.

 

[burns]

check it on vag com see if any faults
mite be down to the cold weather cause the air is denser . the ecu will throw in more fuel to match the dense air

mates got a diesel golf and hes seeing round the 40ish mpg

 

[keefy]

jay.ing, I would say your brakes might be binding to see such a reduction. I'd give it a few days to see if they bed in, and if not get it back there for a look. Binding brakes can cause all sorts of problems.

pow, your 3-4mpg reduction could easily be explained by the 'racier' tyres on the car. They generally offer up a lot more rolling resistance due to softer compound and more aggressive tread pattern.
A few yrs ago in an AutoExpress tyre test, the difference between the best and worst tyre in terms of rolling resistance was 6%.

 

[jay.ing]

Cheers for the inpt keefy. I checked my tyre pressures on tuesday, they were all aroung the 25 psi mark!!!!! all of them! so hopefully that might sort the problem! got a motorway trip home tomorro, and the dealers say they'll havea look too! Im still curious how they got this low when its just been the stealers for wheel problem???

 

[muddyboots]

25psi....yes that could well account for it !

My Passat suffers badly mpg-wise if they tyres aren't right up to what they should be, never been down to 25psi though....!

 

[Clone]

[thread hijack]

I recon i will get 350 miles to my tank i'm at 300 atm or something. I was expecting more than that tbh when i bought it. I can hear my breaks rub when i reverse - could be that?
[/thread hijack]