Tyre / MPG problem?

[rich-m]

I have just had 2 new front tyres fitted, a different brand to last time and the garage (I wont say who but I am not happy with them) said my tracking was way out.  They did it for £20 and since then my MPG has dropped between 10-15 on motorway.  I noticed this immediatley and the car is still pulling slightly to the left.

My questions (I'm not very up on this) are:

1, Will it be the new tyres or alignment (being still wrong/worse than before) that have affected the MPG?

2, Should the pulling on the steering be completely gone now the the tracking has been (supposedly) done?

(I have alreday taken the car back to the garage yesterday and they said yes it was still out but I have just got to work and both economy and steering are still exactly the same -   )

PS - Its a 150PD.

Thanks all.

[topher]

Tracking and tyres shouldn't affect your mpg (unless they fitted the wrong size tyres which will give erroneous reports on the mfa).

I've never driven a mk4 golf that hasn't pulled slightly to the left.. its a feature

[rich-m]

cheers mate, appreciate your reply.  i didnt think it would have much effect but its just strange that since they were fitted and i have been using it as normal, the economy has defo dropped a bit.  Could it be that some tyres just have more rolling resistance when they're new?

The tyres are the right size btw.

[Rhyso]

have you checked the tyre pressure? i know it sounds obvious but I had two new fronts last week and they barely put enough air in to get me going! was a few PSI out. 

put in the correct pressure and everything was back to normal  worth a quick check.

[rich-m]

Yeah I thought that, I'll have look later but even when my old tyres were a bit low (they were on a few occasions) this made no real difference to the mpg.

Just seems strange that since they put the new tyres on and doing the wheel alignment it has dropped quite a bit!

Ta
rich

[New Duncan]

Coincidence - Nothing to do with tyres - Hey what tyres are the new ones  ? ?   anyway ? Ok  sticky tyres like P zeros, maybe a couple of miles or so per gallon, so what !

Check Hall sensor
Check Cat 2 sensor.
Check Turbo waste gate
split in pipework

You need VAGCOM diagnostics if you don't know what it is.  What is your stated MPG from measured calls at the Pumps. Don't rely on the computer readings on the screen, goes way off beam sometimes.  Use Odometer and fuel receipts, then tell us what you are getting. I drive mine hard, drinks petrol, my wife drives steady, and the car is running on air.

[rich-m]

Ok, I'll see if I can get those things checked (?) - a bit technical for me but (Who would you suggest I goto for these checks)?

Anyway, the old Tyres were Pirellis (I know they were a soft compound) and they have been replaced by BF goodrich G-force

Thanks for your reply, I'm gonna go back to garage today and get them to have another look at the tracking as its still pulling to the left.  I know a post above says that its a trademark of a mk4 but surely if i've paid for tracking that should be fixed, should'nt it?