I promised to report back when I had a little more info on the Goodyear tyres I recently fitted to Goth Leo. Apart from the first trip home, recently we have mostly been nipping in to the village and back and we know from previous trips, the efficiency varies a lot on thoose trips, for reasons we have yet to understand.
Today we had to go to Ullapool, 40-45 miles away. This is a trip that absolutely hammered consumption in our previous ICE cars. It's hilly, sometimes, very steeply hilly, very twisty-turny. Over the summer, the absolute best I managed was the car flipping to 4.0 miles/kWHr from 3.9 just as we got into the 20mph zone at the bottom of the big hill dropping down into Ullapool. Most times, I accepted, if not being happy, that we could expect about 3.9 on that trip.
Today was cold and we had the heating on. It was also rainy most of the way and roads were very wet all the way. And at the bottom of the hill as we arrived inn Ullapool, the car was on 3.4miles/kWHr. Not great but not bad either. On the way back it was slightly warmer, and we got 3.7. So at the moment, all we can say is that there may be a slight economy penalty with the Goodyears, but it's not marked.
We will be doing a longer trip of several hundred miles next week so will get a better idea of colder weather economy on these tyres.
But I should add that the car is much more certain on these tyres, especially in the wetter weather. I recall that first test drive and being amazed at how glued to the road the car was, how you could throw it into the corners and all that would happen is the car shouting "More! More!" Well, any suggestion of understeer is gone, and the car tracks absolutely certainly into corners, especially on our poor roads. If you hot bumps in corners, with the factory tyres, you expected to make corrections, or bounce a little with the corners force. Well today it almost felt as though something was missing from the expected ride. And the tyres are a lot quieter too; there is less change in road noise from smooth to pebbled stretches of road.
This is a bit of a relief, as one doesn't know what effect new tyres will have. Often in ICE cars, there is little one can feel*, but there really was a large, noticeable, positive change in the way the car handles. I am still not saying this will suit everyone, as we have specific reasons for needing these tyres, but I am reporting what we have found.
It looks as though there are several threads here about tyres, so in the interest of completeness, I will try to remember to post the results of the longer trip next week. It's due to be a lot colder for that trip, which will be 500-600 miles.
(* - My lovely old Land Rover, which I had from new, a 200) MY Heritage special edition, came with BFG All-Terrains. I got 88000 out of the first set, and we moved north during the second set, where I found that roads here damaged tyres in a way that made running BFGs unsustainable. As a stopgap, I fitted remoulds - I can't for the life of me remember the name, but it was a Spanish company. My goodness, what a difference. Until then I hadn't realised something could be done about the understeer. The car was far more secure on the road, and the tread pattern virtually the same as the BFGs. They didn't last as long, but were 1/3 of the price.)
www.goodyear.eu
The full name is Goodyear Vector 4Seasons Gen-3. Yes, they use the mixture of numbers and characters like that. OK, vector's a good word to use for tyres, as long as no-one thinks it means "to scoot off at a tangent" 
