Conflicted hybrid owner

Hi all,

Thought I'd join up and say hello.

I recently bought a 2007 Prius T4 with 60,000 miles on the clock.
I must admit to having a slight vested interest in them though.
One of the businesses I run sells used hybrids here in the UK so it seemed right to put my own money into the product. I must say it does what it's meant to do extremely well. i.e. it gets me from A to B with no fuss and extremely cheaply.

Now here's the conflicted bit.

I also run a business importing and selling US vehicles here in the UK so one of my other cars is a 2009 Mustang GT/CS convertible. I actually sold my '03 GT coupe to buy the Prius.

So I've got one car doing 20mpg and one doing 55mpg so, in man thinking, I'm getting 38mpg out of the Mustang if I average the fuel consumption for the two cars.

So, hello all.