This may be a stupid noob question but I am curious as I have never owned a sports car, a rotory engine or anything that consumes quite so much oil. Now that I have finished the disclaimer I will move into the question.

As seen in posts here, the little DVD that comes with the 8, and told to me by the dealership that this car can actually consume large volumes of oil so does this negate the need to have it changed every 3k miles? Currently, I am just between 500 and 600 miles so my impression of just how much oil the car consumes may be based on exagerated hear say and forum posts. So, I am just trying to get a clear picture regarding the regular maintenance required of my car with relation to oil. I mean I checked the oil at 500 miles just like the "good book" says and it was a little low so I topped it off. I did not however see anything in the "good book" that makes reference to recommended oil changes.

Again, like I said this may be a stupid noob question but what seems to me to be the exagerations of the 8's oil consumption rate has made me a bit curious. This is the nicest damned car I have ever owned and I want to make sure I do right by it.

 

Nope, you still need to get your oil changed frequently.

I believe there is a maintenance schedule towards the back of our "good book" or you can register with mazdausa.com (under owners) and you can view your car's maintenance on there.

Oil consumption varies a lot on driving conditions. I check my oil every other week to be on the safe side and I rarely need to a whole lot of oil. MAYBE less then 1/2 quart every month...

 

Well, I think the maintenance schedule in the owner's manual specifies either a (severe service) 5K or (normal service) 7K (miles) interval. I used to be a 3K fanatic myself, and I still can't force myself to go 5K or 7K.... If you search on this topic you'll probably find a lot more heat than light here... <g> And you haven't even asked about using synthetic yet!
<LOL>

Remember that the car (6 port engine w/ two oil coolers) holds 7 quarts. When you change it (and filter) you'll find it only takes 4 to fill it up. Even though she uses some oil, I don't think it'd be a good idea to ignore the Mazda's maintenance recommendation. Also remember that the rotary engine generates a lot more heat than a conventional (piston) engine, and it also relies more on the oil to keep critical parts cool as well as lubricated.

I've had my '8 for a little over a year now and I've used a 4K mile interval - if it goes a little longer than that I know I'm still changing it more often than the severe service interval. Also, I've chosen Castrol GTX because of its low ash and high zinc content.

Check out: www.bobistheoilguy.com

BTW, I've tracked my oil consumption and it ranges from about a 1/4 to 1/2 quart per 1000 miles - less than half of what the manual calls normal....

Enjoy your car - it is a wonderful machine!

Beers!

 

i just changed the oil on my 8 last night; i got about 3.5 qts out of the car, which means it used about 1/2 quart for about 1500 miles since my last top-off.

after a few oil change intervals, you will find your own oil use rate with your RX-8, and then you can just check the oil at a certain mileage within an oil change interval (mine's 1500 miles, right in the middle of my 3000 mile oil change interval), top it off, and be done with it

remember, as long as the oil is between the 'low' and 'high' markers on the dipstick, it is safe to drive, probably want to keep it topped off if you're tracking it though lol

 

hehe... okay I did a search and yes the "large volumes" comment was my own little exageration. Thanks for the suggestions and I'll revisit the manual again.

THANKS GUYS!

 

What about going over the "full" marker on the dipstick? I recently got an oil change at the dealer, and he put 5 gallons I believe. It shows well over the "full" mark. He said there is an extra pan or something for excess oil. Is that true?

 

I hope you meant 5 quarts.....

and there is no extra pan for extra oil except for the one you would drain the extra oil into...

 

You've probably already noted that most writers on this forum change oil at much shorter intervals (mostly every 3000) than the manual's recommendation (5000-7000). Some of these are experienced rotorheads with sound arguments favoring the short interval; others (like myself) just have an emotional basis ("want to take care of my baby"). I aim for 3,000 miles, but sometimes stretch to 4,000 or so. (I live 400 miles from my favorite dealer).

 

its a car, the owners manual (that your should read, its the cars 'instructions') says that you should get the oil changed ever 5000-7500k miles (depending on conditions) as a rule of thumb, change your oil ever 3K miles/6months if you use regular oil (and I do the same for syn although you could take that to around 5k miles/6months).....if you really want to know how often to change your oil, get a UOA every time you change the oil...to give you an idication of how often you should change it based on where you live and how you drive (rpms, temps, ect).

Ask yourself, do you want your car to last and 'average ammount of time' and perform 'average'.....then change your oil ever 5000 or 7500 miles like mazda says you need to so you can keep your warranty.

If you want your car to run its best, and last a good while, change the oil every 3k miles with a good quality oil/filter.

Many have asked, "if I have to keep toping the oil off every couple weeks, why do I need to change the oil, I keep putting good oil in it". Well you dont get the pick what oil in the motor your buring......the engine cant just burn the oldest oil......so if you never change the oil, there is always gonna be some of the oldest, bad oil left in the motor.

Compound that by the fact that even when you do change the oil, some if left in the oil coolers, ect.....so you still dont get all of it out anyway.....

Plus the car uses 4qt's of oil every oil change, if your changing the oil ever 5k miles, it doesnt even burn that much oil in that ammount of time, so you would be changing the oil as often as you should anyway......does that make sense?

Dont forget that up to 30% of a rotarys cooling is done via oil, and its the only thing that protects the car, at ~$3 a qt for good non-syn oil.....is the 30 mins it takes to change it yourself really worth so much that you would lessen the life of the car?

$20 today or $2000 tommorow....your choice.

 

I spoke with one of the reps at Rosenthal Mazda today. He has been great with service questions on my 92 Miata. He says they recommend changing the oil every 3500 miles on an RX8. I'm probably going to stick to that. Remember to check oil every other fill up at the rotary burns oil.

As far as, someone mentioned this above, the synth oil, it's a no-no. They told me the synth does not burn well and does not do well with the engine gaskets/seals (forgot exactly what he said, gaskets or seals, so that's my interpretation of the stuff in a rotary engine).

Hope this helps.

 

The reason why the short interval oil change is recommended is because over time your oil turns dirty and its squirt into the combustion chambers for lubrication. Try to keep oil level at full if possible, less oil means more heat in engine.

Side note: Synthetic burns better than mineral oil