Oil Consumption
 

I just bought a 2004 RX-8 (dealer demo) with about 7,800 miles. Love it. love it. love it! It's by far the most fun car I have ever owned. OK...to the question.

I was recently on a road trip and had the low engine oil light come on. I had just put on about 800 miles since I picked up at the dealership. Getting approx 260 miles/tank on gas...so was in the neighborhood of 3rd tank. Now I KNOW that a rotary engine burns oil. But 2 qts in 800 miles?

I called the dealership (was quite PO'd) and was told that per Mazda specs anything less than 1 QT per 600 miles was "acceptable" oil consumption.

Any thoughts? What should I expect?

~Tony

Mine with 5500 miles burns about 1/4 qt in 600 miles. I do not drive it real hard but always rev it up every 50 miles. I think that would be the normal in the dead center of the bell shape curve. "I called the dealership (was quite PO'd) and was told that per Mazda specs anything less than 1 QT per 600 miles was "acceptable" oil consumption. You are burning at a rate of 1 qt every 400 miles which means it is less then Mazda standard.

So far I've got 5200 miles on my 6MT. I added about 1 quart total before my first oil change at 3000 miles. Since the oil change I haven't needed to add any- the dipstick reads just barely below "F".

My results are somewhat skewed since my "8" was overfilled on delivery, and by the dealer at the first oil change. Looking back it seemed odd that I'd go the first 2000 miles without needing oil, checking it regularly, then all of a sudden having it be down half!

2 quarts in 800 miles sounds way over-the-top. Did you know your 8's oil level when you picked it up? When you change the oil you replace something like 3.75 quarts. That's over 50%! Hopefully no damage came of it.

Hmm I just put my first 1000 miles and my oil level is still high... how low is it suppose to go?

Can someone answer this question: I have 27xx miles on my 8, and I checked the oil, and it is very close to the L....should I go ahead and add some 5-20? Do I have to drain all the oil out and add a new batch? ie, can i just add some oil to bring the level up a bit?

thanks

Just top it up. Oh, and please get in the habit of checking it more often! Mazda recommends checking it every other fill up (a bit excessive), you ought to get in the habit of checking it (and topping off if necessary) every 1000 miles or so. Remember, this engine uses oil by design, so don't ignore it. FWIW, I typically add about a quart every 2500 miles or so.

Definitely top it off up to "F". When you get to 3K miles replace the whole batch and keep changing it fully at that interval, topping it up in-between.

great...thanks fellas

My oil consumption has gone down since the M flash. Unless it's just a coincidence. No change in driving habits.

I used to add almost a full quart every 2500 miles. Since my last oil change/M-flash appointment, I've gone 2600 miles and added about 1/3 qt to top it off.

Not coincidence - I'm observing the same changes.

rx8cited

Would anyone recommend a Synthetic Oil? And do you see any improvements/differences with this car?

Ok please ignore the 1st question, as I am checking out the Tech Garage thread related to Synthetic Oil.

dam i had my cars for like 3 months and never notice there an L and f on the oil stick or are you guys talking about something else?

Oil consumption
 

We took part in the oil consumption tests for the RX-8 in Europe, a single car was past to several European countries and the oil consumption under different driving conditions was recorded. On one journey (high speed on twisty minor roads) of 155 miles the test car, a 190hp 5 speed manual, used just over half litre of oil so 2 quarts in 800 miles does not sound worrying.

First you gotta pull the dipstick out to see the marks ;)

Seriously though, the marks are fairly hard to see, and especially so to discern the actual oil level itself on the (low contrast/smooth) dipstick. *sigh*

Just pull out the dipstick and look closely a couple of inches from the end; it'll be very obvious when you see the marks. Generally you'll want to keep it close to 'F' (without going over).

-jd.

thanks jdl

Well for me my first oil change was at 2,500K. Then my next oil change was at 5,400K. I check my oil every fill up and I was not short a qt? and i drive my car every day to 2 jobs + going out like tonight:)...

Jers8,

I was told by my dealer to NEVER use synthetic in the 8 because of the way it uses oil. I was told that a pure synthetic will not spray correctly into the engine. Maybe one of the better informed people here could offer a better explination as to the mechanics of this. In the meantime, a regular and high-quality engine oil should suffice such as Castrol or Valvoline.

Also, I know Clem has repeated what has been pounded into every American's head regarding oil changes, but Mazda has a different schedule in the manual. On page 8-4 of the RX-8 Operator's Manual, is Schedule 1. Maintenance Schedule 1 should be followed if your 8 is not being operated under the qualifiers on page 8-3 including dusty conditions, high humidity, rough/muddy roads, Canada or Puerto Rico. I suppose Canada and Puerto Rico qualify as all of the above. Anyway, Schedule 1 states that Engine oil and filter should be replaced every 7,500 miles or 7.5 months. Schedule 2 (for those in Canada where it's dusty, muddy and humid) calls for replacement every 5,000 miles or 5 months.

To me, taking a bit more time between oil changes than what we're used to makes a bit of sense for two reasons. The rotary doesn't bathe valves, pistons, rods, etc. in oil, return the oil to the sump and then bathe again. It uses it in a spray fashion into the combustion chamber where it is burned and only a small fraction returned to the pump. Second, after 3,000 miles without a change, the oil is still clear and clean. No brown, dirty oil you find after a couple hundred miles in a piston type engine. Currently my oil has 6,000 miles on it and it is still clear and clean. I have to hold the dipstick up to the light to see the oil on it. So, if the oil is still clean of contaminants, why waste your money on changing it? Additives that may have been lost due to use in the engine will be replaced when you top off the oil. Save your cash for down the road when you need to replace the $250 tires.

Anyway, my 2 cents on the oil issue. Sorry Tony, I don't have any input on your oil consumption issue other than keep a close eye on it and have the dealer take a look at it as soon as they can schedule you in.

I didn't see this anywhere in the post and it is in the manual, but I found it useful. The amount of oil needed between the L and F mark on the stick is 1.3 qts. That will help in topping it off, it did me at least. I check mine every 1k and end up adding a little. Better to be safe than sorry. Hope this helps.

I have been changing my oil on the 5,000 mile plan (well, not me, the dealer, thanks to the mazda maintenance card plan), but I end up adding a quart about 2500-3000 miles into it. This has been predictable for the 4 oil changes I've had done. Because of this, I have relaxed checking my oil to about every 1000 miles. The only problem would arrise with an actual leak, which is unlikely, and the good thing is that the car has an oil level sensor, which lights LONG before the pump would lose oil level. One probably could run the car until the light came on, and odds are would never have any problems, but of course, that is hardly prudent.

EDIT: Oh yeah, something to point out, after every oil change I've gotten from the dealer, the dip stick has been up over full... Maybe something they do to keep people from running it dry. Anyways, an overfull sump in a rotary isn't near as bad as a piston engine, as it's not liek the crank will be splashing in to the pool.

Keep a bottle of 5w20 weight oil in your trunk. If the oil light comes on, stop and check the oil level immediately. We had one genius here drive three days with the oil light on, and the engine seized (no good). He then tried to blame Mazda, and get them to replace the engine under warranty (laugh my ass off).

I have about 1400 miles on mine, and I have added a little oil twice (less than 1/2 quart total), but I am anal about caring for my stuff, and I check every other tank full. Oil is cheap, new engines are not.

This car is not for everyone.

My RX8 was slightly over filled when I picked it up in March. I got an oil change at 1000 mi and it was slightly over filled ( differant dealer ). After a 2300 mi trip Houston-Orlando-Houston I added the one Qt. it was down. Some one said the amount of oil between F and L marks is 1.3 QTs. , I thought it was 1.7 Qts. Anyone know for sure?

don't forget about the TSB on some of the older cars (mine) where the oil pan had to be replaced. When the oil light came on, how fast were you going? If your oil light comes on above around 4k rpms (78mph or so in 6th) that's what the problem is, I don't think anyone mentioned this yet.

The distance between L and F on the dipstick is 1.7 US quarts per the US Owner's Manual page 8-10.

rx8cited

I think the car is programmed to use more oil during the first 6,000 miles or so. I had to add about a quart every thousand miles for the first 6,000 but I haven't had to add any between oil changes since. I've been changing the oil every 5,000 and I'm at a little over 14,000 now.

mine doesn't have and L or F (that I recall), it does have two VERY obvious lines across the flats of the dipstick.