By what measure? If you are going for boasting rights, maybe. But you won't get top dollar selling used tires and rims, so you have to figure at least 50% of the cost of new tires and rims being the payoff target.
Napkin calculation suggests you may save less than $100 per year assuming 20,000km and $.12/kWh utility rates. You might get an extra 10-15kms per charge, so on trips it might be a little help, but not a game changer.
BTW, kW are instantaneous power and kWh are quantity. I only mention this because using incorrect terminology tends to confuse people. You are trying to say the equivalent of miles (or kms) per gallon (or liter). Or in this case, how many gallons or liters needed to go 100 miles or kms.
I went through this mental exercise when I leased mine, but figured it wouldn't add enough range to skip the short charge/restroom break I need on my most common road trip route. Currently, I would arrive at the main charging stop which is about 260 miles from home with little to no remaining range (and a screeching co-pilot/wife) if I skipped the short charge 60 miles short of it. Putting smaller rims/tires might increase that to 20-30 miles which is still pretty tight, but I generally need to stop to use restrooms anyway, so I just couldn't justify the expense.