"Winter" tires

For some time now I wanted to switch to 13" tires. My favourite rims are the KN Jupiter, quite an old design but looking good. When I bought them, I didn't pay attention to the bolt scheme and couldn't mount them. I keep them stocked, maybe one day they will end as decoration for a new garage...

My second choice is the classic Minilite style. A good friend sold me a set with Federal tires and I really like the look it gives to my car.
But it is not all about looks! This car type is all about weight to power ratio. Since I don't have a lot of power, weight savings are very welcome. Here we go, let's talk about figures:
What I had on the car until now at the front 195mm 15" Revolution rim 16.9kg
What I had on the car until now at the rear  225mm 15" Revolution rim 18.0kg
What I have now on the car at the front       175mm 13"     Minilite rim 12.2kg
What I have now on the car at the rear        205mm 13"     Minilite rim 14.2kg
Ok, the front tires are quite small and I may opt for 185 or 195 when I switch to semi-slicks, but at least I want to drive the car for test with the Federal tires for some time. Net weight savings:
front 4.7kg per side = 9.4kg
rear  3.8kg per side = 7.6kg
for a total of 17kg
Impressive!
Cheers.