MK5 Golf GTI

All Things Mk5 => How to Guides / Troubleshooting => Topic started by: liam on January 26, 2015, 12:32:37 pm

Title: Sudden drop in MPG?
Post by: liam on January 26, 2015, 12:32:37 pm
For the last two months i've been getting maximum of 24.4mpg. I do a lot of town driving and on the way to work i rarely exceed 40mph. Round September time i was getting about 29/30 and at one point (i think the car had a funny moment) it went up to 39mpg really quickly with no change to how i was driving. It's had the Diverter valve replaced in the last 6 months so i can't imagine it is that again, could it be running rich? what would cause that? or are there any other theories you guys might have? I'm driving to Cornwall from Oxfordshire in a few weeks and 24mpg for a 200 mile drive will be a killer.
Title: Re: Sudden drop in MPG?
Post by: GrayMK5GTI on January 26, 2015, 12:49:03 pm
It's the cold winter air. It's affecting everyone's cars.

You should get mid-high 30s on a long motorway run, if you take it steady  :happy2:
Title: Re: Sudden drop in MPG?
Post by: Beej on January 26, 2015, 01:49:39 pm
I do constant town to work and back, and I think the best I've seen is 26 mpg (end November) but over the last few weeks it's more like 24 ish
Title: Re: Sudden drop in MPG?
Post by: dansmith180 on January 26, 2015, 04:39:51 pm
Is there any chance you've got a caliper sticking? Even if its only sticking a bit it can cause a big MPG decrease.

Look out for 1 wheel being particularly dirty and might be really hot after decent length journeys as well.

Otherwise as above probably just the weather.
Title: Re: Sudden drop in MPG?
Post by: Saintsteve on January 26, 2015, 04:53:29 pm
It's the cold winter air. It's affecting everyone's cars.

You should get mid-high 30s on a long motorway run, if you take it steady  :happy2:

This  :happy2:
Title: Re: Sudden drop in MPG?
Post by: Beej on January 26, 2015, 05:22:04 pm
Is there any chance you've got a caliper sticking? Even if its only sticking a bit it can cause a big MPG decrease.

Look out for 1 wheel being particularly dirty and might be really hot after decent length journeys as well.

Otherwise as above probably just the weather.
My car was in for a service last week and all reports were good , so mine appear to be ok.....
Title: Re: Sudden drop in MPG?
Post by: wesrev87 on January 26, 2015, 11:04:18 pm
I think it is just the winter. I was getting mid to high 30s up to August/September and am now lucky if I get 33 mpg  :sad1:
Title: Re: Sudden drop in MPG?
Post by: Dave(tm) on January 26, 2015, 11:53:45 pm
I think it is just the winter. I was getting mid to high 30s up to August/September and am now lucky if I get 33 mpg  :sad1:

Yeah I'm hoping for this too...but it's been cold since I got the car, so let's see!

Dave
Title: Re: Sudden drop in MPG?
Post by: liam on January 27, 2015, 12:56:21 pm
Is there any chance you've got a caliper sticking? Even if its only sticking a bit it can cause a big MPG decrease.

Look out for 1 wheel being particularly dirty and might be really hot after decent length journeys as well.

Otherwise as above probably just the weather.

I'll check it out cheers!