Extra MPG

[Landcrab1800]

Got a good one for you petrol heads,

My MG Montego has always averaged 30mpg at 70- 75 on the motorway.
Did a 227 mile journey north, again 30 mpg.
Came back south and got 34 mpg.
The only difference is that I was carrying more weight AND (like a plonker) left my petrol cap at the petrol station.

Can anyone work this out?:confused: :banghead: :confused:

[SimonR]

AFAIK going North it is generally up hill all the way, whereas going south it's the opposite.

That's one reason. It's odd that you experienced the effect with extra load. How much extra load?

[Landcrab1800]

Well, we took up half a dozen paperbacks and a couple of loafs but came back with a boot fool of stuff AND very full stomaches curtisy of the inlaws.

The boot cotained a windscreen panel, a few small bits for the landcrab, food, saddle, 3 large dustbins, odds and sods and a few? of her clothes.

[MGTurbo]

Interesting. I can get 35mpg from my Turbo :(

[E_T_V]

Perhaps the long journey blasted out a load of crap and made it run leaner on the way back. Also the amount of fuel in the tank is easy to misjudge, it only takes a slight slope on the garage forecourt to make a lot of difference to what you can put in your tank.

Also of course there may be traffic jam issues and driving just a little faster makes your fuel consumption a lot worse.

[J199 HHG]

A good tailwind can make quite a difference.