Bigger chunks on tyres will increase fuel used (someone will spout lower rolling resistance - but forget the windage factor) worn tyres are always more fuel efficient - for road testing fo rmpg with trucks a miniumu tread depth was always specified - and the manufacturers press prep teams always had them absolutely on the wire because a tiny bit of tread depth difference translated back in measurable fuel used.
NOISE - chunky tyres make more noise too - if you are travelling distance, that makes a difference to your head at the end.
Tourances have been the best overall for me too - and how did anyone get through a set in 4500 miles? It would make me cry if I had to buy tyres nearly THREE TIMES as often...I get between 12000 and 14000 a set from mine on the Adv. What you doing? You're wanging the throttle open and then heaving on the brakes at the roundabouts, thats what you're doing!
I am paying for my own fuel, tyres, brakes, clutch....everything. If I can eek another 30 miles out of a tankful, I will. Likewise with tyres....they have to last me 12,000 miles or I go to the woods and cut some fresh birch twigs. As for brakes, what do you want brakes for? They only slow you down - look a bit further ahead and roll off the throttle and you don't need to touch them until it is time to fill up the tank or you have reached the end of the road. I had to put new rear pads in at 45,000 miles and the front ones do 30,000 - just on two sets in 65,000 miles on the Adv with its whining motor thing.
Back to tyres....tourance for miles, grip and fuel economy...and you can get good deals too if you keep your eyes open. I bought this set for £139 delivered (the PAIR). That is only just over 1p per mile. I can live with that!
