newbie with mpg trouble

**jasonjohns** · 22-10-2007,08:22 PM

First of all hi to everyone from a newbie to the site and to VWs

I bought my 2000 passat estate (tdi) last week. At first i was delighted with the mpg figures i was seeing before my eyes. (45 ish)
Now i only seem to be getting 35 mpg , its not motorway driving but even for 30-40 mph journeys, this does seem low to me.

I have just fitted 18 inch alloys to it and wonder if this could be the cause of the drop in mpg. I just wouldnt have thought it could make such a difference.

Any advice would be appreciated

**Crasher** · 22-10-2007,08:59 PM

Hello and welcome to the forum. As long as you are running 225/40 18 tyres there is no rolling radius problem and the extra width won't hurt the consumption that much by increased drag. Do you feel the power is OK?

**jasonjohns** · 23-10-2007,12:15 PM

Thanks for your reply

Ye i am running 225/40s and thats what i imagined, that it couldnt make that much difference. Im finding it hard to get mpg anywhere near the 40s and i am only feathering the gas pedal.
It doesnt seem to be struggling for power to be honest, it does pull. I guess your thinking the MAF sensor as i have read somewhere. Would this affect fuel consumption too? Any other possibilities?

Cheers
Jason

Big G · 23-10-2007,01:04 PM

Originally Posted by jasonjohns

Thanks for your reply

Ye i am running 225/40s and thats what i imagined, that it couldnt make that much difference. Im finding it hard to get mpg anywhere near the 40s and i am only feathering the gas pedal.
It doesnt seem to be struggling for power to be honest, it does pull. I guess your thinking the MAF sensor as i have read somewhere. Would this affect fuel consumption too? Any other possibilities?

Cheers
Jason

I had a similar problem which was fixed with a new air filter as the other one was full of crap, dust and leaves. Was getting 40ish the after the air filter change to went to 49-50ish!

**Crasher** · 23-10-2007,01:34 PM

I was thinking MAF but not if it pulls well.

**fozzie** · 23-10-2007,02:00 PM

only being 30/40 mph is not great as you say, its not motorway.
I find it hurts stop start stop start, as you keep having to pull away!
How long is the distance? Once you have gone through the stop start driving, try and reset the trip on the move and see how it settles down!

**fozzie** · 23-10-2007,02:06 PM

The reports that owners are putting on the site are probably the extra urban/combined cycle MPG's side of driving.

If you are bordering on the side of the urban mpg's you are looking at 35 ish.

Sorry couldnt find a site that shows the urban-extra urban-combined cycle mpg's.

**jasonjohns** · 23-10-2007,03:28 PM

I mean its not sat in traffic or anything, its what i would call a normal car journey of about 5 miles stopping for odd traffic light etc. I have spoke to people with tdis who say they average 45 on way to work! i dont expect 50 as some figures say but im getting no way near that at any point, not even on motorway.

Would the air filter make the difference?
Does any1 know of a how to guide on changing the MAF, i cant seem to find one anywhere