Thanks to Fuztupnz from RX8Club, I got the Engine Coolant flush/change done at his place.
There’s two bolts to remove, one on the radiator and another on the engine block just above the oil pan.
As always, the RX8Club forum’s DIY section had a great tutorial and the pictures were a great help.
I did two flush with distilled water, and then used Prestone Antifreeze (concentrate)
it took way less coolant thank I was expected. both two flash as well as re-fill, my car took only 2 Gallons, while I was expected more close to 2.5 Gallons. I’ll check the level again tomorrow to see if it will take a little more.
Anyways, I haven’t calculated my gas mileage, for a while, and here’s what I got for last couple fills.
19.804 MPG: almost all highway, just a little drive around in town in between.
20.073 MPG: less highway than above, but with some backroad driving.
it’s surprisingly good gas mileage for RX-8. don’t really know how though… ^^;
