I read in the owner's manual that the distance between the full and low marks on the oil dipstick represents 1.8 qts of oil. Is the oil level on the dipstick proportionate to the amount of oil that needs to be added? In other words, does halfway between full and low represent 0.9 qts, one third between full and low 0.6 qts, etc.? Getting ready to add some oil tomorrow (Castrol GTX 5w-20 for anyone who isn't sick of hearing about what kind of oil people use).

 

Yes thats it. How many miles are on this oil change and where is it on the dip stick.

 

I don't recall reading that data point, but from personal experience mine doesn't seem to be 1.8 quarts. It may be a good idea to check the stick at an interval before pouring in that much.

 

i pour in a half quart at a time, then recheck the dip stick. since i change the oil every 3k miles, i tend to put in one quart between oil changes..

 

Well, you had to make me go out to the car and get the owner's manual, didn't you? :p

Page 8-11: "The distance between L and F on the dipstick represents the following:
"L (U.S. qt, Imp qt): 1.7 (1.8, 1.5)"

 

I have over 15k on mine and never added oil yet. I just change the oil every 3k. It's only 15-30 dollars and well worth it. This is my 7th rotary and I know not my last.

 

To be safe, follow Jasons advice and add no more than half a quart, let it settle for a few minutes, and recheck. I've overshot my full line a couple times by trying to put too much in at once.

 

I'm just adding oil, not changing it. Last time I checked, with around 600 miles on the car, it was about a quarter to a third down. That was about 200 miles ago. I know, I could wait, but I'm actually looking forward to this! I'm a freak.

 

Your oil consumption should slow down as you clock more miles. As I've just now hit 10k, my oil consumption is half of what it was during the first 2k miles... and with oil changes every 2.5k, the need to add oil between changes has diminished to the point of being unnecessary.

 

Well that's not fun! I say we demand that Mazda fix this! :p Non-technical people like myself need things to do to feel like I'm working on my car without really working on it!

 

Class action lawsuit!!!! :D

Seriously though... if you really want to pretend to work on it, oil changes are a breeze and a great way to bond with your 8. And you can hide from your wife underneath the car to avoid more boring weekend chores .

 

Yes, but after about 4 hours of laying underneath the car, doesn't it get a little strange?

 

And besides, per one idiot on this forum a few weeks ago, the RX-8 should get 10,000 miles between quarts! How dare Mazda communicate wrong, or the automotive press accidentally quote them incorrectly. The outrage of it!

 

Castrol 5W-20 is what I go with, too. Use that funnel, though, to pour it in--the stuff is thin.

I'm making a trip up to No. Cal. on Sunday and I'll check the oil before I go, but doubt that I'll need much. My oil consumption appears to be in line with many others here--meaning, not an alarming amount at all.

 

Unlike a piston engine with a crank shaft rotating just above the oil in the pan, you can overfill the oil level in the RX8, within reason, without any problems. Just don't get extreem as oil could enter the ventulation system if real overfilled. But even a 1/2" above the full mark will not cause any problem.

I was actually real surprised when I bought my RX8 that the low mark was the danger mark and the 1.8 qts. low as mentioned. I guess the engineers forgot about 1974~5 problems. They had so much problem of peopler running the rotary low of oil that they had a service campaign where the end of the dip stick was cut off at the danger mark and restamped at the 1 qt. low level. Customers were actually sent letters to come in for an exchange.

What ever you do don't get in to a habbit of not checking your oil every time you get fuel. When new only the metering pump uses oil and your consumption will be directly related to how much throttle you use and the engine rpm. Later when the internal oil seals wear the oil consumption can suddenly increase. (Can explaine why the rotary oil seals are different than other engines if you want, but won't now.) If you miss this the rotor will overheat and all hell can result in a locked up engine.

 

How many miles do you have one your RX-8? Do you really check it every time you fill up and what's your car's oil consumption?

I've had my car long enough to know that with my driving style I'll be down about 1/2 a quart after about 1200 miles, so I check the oil every 3rd fill-up (~750 miles).

BTW, here's what the manual says regarding checking the oil level:
"It’s OK between L and F. But if it’s near or below L, add enough oil to bring the level to F."

I add oil if it's below the 1/2 way mark, not wait til it's near or below L as they suggest.