can I have your used oil? ^

The oil molecules are polar, like water. I used the term "static charge" because it's easier for people who don't remember their chemistry classes to understand.

Okay, that's just silly. No oil wears out that quickly.

Don't wait any longer then 6 months between changes if you drive very little. Mazda requires that...

Hey, you made me search some more!

You're close; diester synthetics (group v) have a polar characteristic that helps scrub off deposits, and adhear to metal better than any other motor oil.

Most all other oils and motor oils are not considered polar, but they came from the ground whereas esters are manufactered from fatty acids in plants and animals.

The best real synthetic oils are PAO (group IV), and ester (group V), but PAO shrinks seals, and esters swell seals, so the refiners (manufacterers) experiment with mixtures of these two to get their perceived best ratio.

Amsoil is hyping that good ester characteristic without mentioning that if it is all ester it might be hard on seals if they swell.

The cost of repairing an RX8 in my country is an arm and a leg (and possibly a kidney). Since its a weekend car for me, I pamper it quite a bit lol :)

Roger that. I made an appointment for an oil change. I am using the Mazda dealership backed up with paperwork in case I have engine issues years from now. I dont want them dicking me around.

1100 miles is just ridiculous and totally unnecessary, every 3000 miles is fine ;)
No wonder the world is having an Oil shortage...it is your fault!

I go every 5000 KMS or 3000 miles, and use dino 15W40.

If Mazda says 5k miles, than changing it more often is just more profit for the oil company and the oil change places. In many aspects, the rotary makes this even more true. If you're adding a quart every 1k miles, then you're almost getting a full oil change between the 5k miles. Each time you add a new quart, you're adding more of the things that are being consumed - most importantly the binders and wear inhibitors. Even more so with synthetic - since the molecular chains in synthetic oils tend to survive longer under engine conditions. Changing more frequently certainly doesn't hurt, so if it makes you feel better, go for it. There is likely some benefit to it, though possible immeasurable.

Keep in mind that car manufacturers have a vested interest in doing everything possible to insure your engine lasts. If they thought that changing the oil at 3k miles would noticeably extend the expected lifespan of the engine, they would recommend it...particularly since many people have already become accustomed to this interval. The oil change places have vested interest in convincing you to change your oil as often as possible.

This is not true.
In 5k miles you add what, 2qts? Your oil system keeps around 8 and during an oil change through the pan it is a stretch to take out 5qts. Since the new oil mixes to the old one the added quarts get just as dirty.
What's important is to change the oil when it's needed for the use you make of the car.
What if you lived in a country where oil changes are often performed every 20.000kms? Here Mazda says to change the oil that often, or yearly...

I do the same exact thing.

On top of all that, Mazda recommends every 5k only if certain conditions are met, otherwise do schedule 2 maintenance which is the 3k mile one. Heres the list from the manual, basically if you drive your car in any type of city you will be on schedule 2 which is the "replace stuff sooner" schedule.

http://img703.imageshack.us/img703/6...aintenance.png

It looks to be true for me. I'll be adding nearly a quart today after a little over 1000 miles. That would be nearly 4 quarts in 5000 miles. Since a change is ~5 quarts, that is nearly an entire oil change.

Mine is a 2009, BTW - does the Series II meter more oil into the chamber?

Well s2's have a third oil injector but I wouldn't think that would make it do twice as much oil. I know I don't use anywhere close to 1 quart in 1k miles.

Well, an oil change is only effective if you remove a great percentage of the oil, are you aware of that?

According to most accounts I've read here, the Series II motor should meter oil more efficiently, since it distributes it better with the 3 injectors. My 2009 uses about 1 quart every 3,000 miles. However it is an A/T, which turns much slower in top gear on the highway than a M/T, so I would expect it to use less oil than a M/T.

I have a 2010 GT with a stick and I've been tracking oil usage and it uses a quart every 1000 miles. I add about a 1/2 a bottle every 500 or so miles, as indicated by the level on the dipstick.

I'm glad it's using the amount it is, because more oil used means longer-life engine. Not sure how good it is for the cat and carbon build-up though.

Just to add: I drive mostly highways, about 50 miles per day during the week, revving close to the red line at least once a trip.

Compared to most accounts of oil consumption posted here, that seems a bit excessive for regular highway driving...

Are YOU aware that when you change your oil, you're only changing about half of it? As I understand it, the entire oil system in the RX8 holds about 7 quarts (I'm happy to be educated here) but less than 4 are in the oil pan - and therefore you are only changing ~half of it. There is little difference between adding 1 quart of fresh oil every 1000 miles vs adding 4 quarts every 4000 miles.

BTW, I did mis-speak earlier - the oil change capacity is less than 4 quarts, rather than 5 quarts.

I actually flush the oil coolers as well while moving the rear tyres with the car in gear...
Just adding 1qt of oil to a 7\8qt system means nothing, oil quality wise.

Just doing a 4qt oil change means changing only half of the oil and we agree, that's why oil changes should be frequent :)
You have the luck of having blackstone labs available to you, it will be easy to determine when to change your oil with their help :)

The correct numbers - at least in my owner's manual - are every 7.5K miles for regular and every 5K miles for 'severe duty' service.
I change mine every 5K, even though I drive a lot on the freeway at cruising speed so I would qualify for the 7.5K regular schedule.
Won't go lower than 5K since it's not necessary IMO.

I get out over 4 quarts per oil change, you just have to do it right. Its not a lot more but I'm still happy with what I get out.



Tamas even at 2000-2500 miles my oil is looking filthy so 3k is the max I would go. If your willing to go more that's your call, good luck to you.

I'm with you ...

I drive on lots of wet grimy roads and spend a fair amount of time in stop/go traffic. Every 3k for me.

I'll agree that our oil looks shitty real soon after changing, but looks are not a test. Diesel engines blacken the oil worse, and some of them can go 50k miles on a change.

If we could get all the oil out on a drain, I'd do Mazda's maximum drain of 7.5k.