2004 Mazda RX8 Automatic 84,000 miles
What's the bonafide preferable brand/weight of oil for the '04 RX8 Auto series? I know it specifies 5w20 and " never" synthetic but I've read ample evidence to support the pros and cons both these aspects. Some say only synthetic and some say 5w30 or even 40 is ok, since the engine is known for getting so hot. So, what would Mazda put it in at a regular oil change at around 84,000 miles? Also, I've read tons of enough about a faulty coolant gauge for the '04 models and I've been having sporadic heart attacks when I see that light flash on/off. What's the deal. I never rag the car but I will occasionally screw it on for a stretch, maybe 3 miles tops. And every time I do, every time I'll get the light after about 15 seconds of speed until I slow down and lately I've been smelling a burning smell. All knowledge here say it's coolant fluid. No smoke or anything, just a smell. Never overheats, all my fluid levels are accurate. But the smell stays and only when I get on it. Even for a few secs. If I drive slow and steady it's all ok unless I drive for over an hour or so. Then the smell will come but if I " gun it" it'll come immediately. No smoke or anything either? Side Note/Question: I've also heard the myths of changing the tranny/differential fluid. What's a proper consenus? All of these backyard mechanics either are 100% sure it's a grand idea or 100% sure it's a horrid idea, i.E. I could knock some gunk loose, etc. I would prefer to change it all, have fresh fluids and fresh filters< ---personal opinion but if it's really risky then I'd like to know. Much thanks for any info, insight, and direction.