Firts time i need to top my oil up on my o9 RX8 R3 and stupid me bought 2 1Ltr bottles of Shell HX7 10 W 40. Now i am just asking if that will be okay for my RX8 or should i change it to onther oil. I have read the manual book but i am still not sure. Need to top it up now.

Just want to know if it will be ok.

 

https://www.rx8club.com/series-i-tech-garage-22/oil-5w30-10w40-43172/

It depends on where exactly you live but you'll be fine. Your car doesn't know what type of oil you put in it and the viscosity shouldn't be that much different as to effect how much the OMP injects. Plus it will just mix with whatever other oil you still have in there and you're only topping it off, not filling up the tank.

Just read up on the millions of oil threads on here and make your own decision.

 

10w40 is fine for UK climate.

What weight does your owner's manual say? In the US it's 5w20, lots of other places say 5w30. The Australian owner's manual has a chart showing a whole bunch of grades depending on temperature. As I recall, 10w40 is OK anywhere except the tropics or the polar regions.

When you top up you can use almost anything because you still have mostly what was in there to begin with, and the weights average.

Ken