[kingsway]

I'd suggest checking that your wheels are turning freely... One of my rear wheels brakes were binding from corrosion caused by winter road salt - I was still getting good mileage, but it seems it could have been even better!!

I took both calipers off, cleaned up and lubricated (with copper grease) the rubbing surfaces and wheels are turning much more smoothly!

It's easy to check - all for the 'cost' of just jacking up each wheel in turn - or getting your local tyre dealer to put your car up in the air for a couple of minutes.