23mpg Primera 2002

Primera's and other cars sometimes suffer from a brake caliper that doesn't come back free from the disc. The pressure of the hydraulic brake pushes the cylinder against the disc. Usually when you release the brake pedal, the piston moves back ever so slightly, coming just free of the disc. After some years, one or more may not come loose anymore.
The brake piston is then dirty or rusty.
You can imagine that driving with a brake on increases fuel consumption. It also wears down brake pads and discs pretty fast.
Then the brake caliper needs cleaning or refurbishing. If it's very bad, the whole caliper may need replacing.
Usually the brake pads then also need replacing, sometimes also the discs, if it's been going on long enough.
And if you then still ignore it, the friction of the brake may heat up the entire wheel hub so much that the wheel bearing is affected, the grease inside then isn't working anymore.
It pays to check sooner than later.
My P12 had it last year, the disc was very hot, that's how I noticed. I had to refurb the caliper and put new discs and pads on. Have to do it in pairs, to avoid uneven braking.

is there any links on here to show you how to refusa a Caliper ? i have this problemproblem

I think Ant has written a guide in the "how to" section.

I was recently unimpressed with the economy of my car 2.2dti, computer talks rubbish, for 37 read 42mpg mine might even get to 50 if driven carefully I have also had trouble with the off side caliper and when checked one side was not returning, cleaned out and greased (copper) and now all is well, I am looking forward to better still. What I want to know is what tyre choices are there that could affect fuel consumption.