my crapster gets 35 mpg average on a good day and a new starter is 50 bucks
and it's not hard to change.
but any other mods, like thinner oil seems to not affect the life of a gearbox/ engine really that much, if you maintain oil levels and change often enough.
It'll wear out faster, for sure, but for example a well designed gearbox often outlasts the engine. And engines in general last nowadays very well.
And at higher miles, the car itself will be worn.
Maybe if you want to keep the car, you should not do any radical tests with lubricants.
warm air intake should not really do anything bad in a long run, as many cars have some type of wai system OEM, and still last
I use a 20 buck bluetooth-OBD tool to readout values from my car. I can also delete fault codes= saved money because a shop is not needed.
I don't care about my crapster, the parts to it are so cheap, so i can replace them as needed.
Pistons, rings, syncros, etc.
almost all indvidual parts for my car have prices counted in tens of bucks, not in hundreds
Russians are very stubborn with owning a car well beyond their designed life. Lotsa aftermarket.