View Full Version : How often do you plan to change oil?


fastrunner
01-07-2004, 07:37 PM
Ok, how many of you guys/gals follow the Mazda guide for oil changes on the 8?

8_wannabe
01-07-2004, 08:18 PM
How about the recommended interval of 7500 miles? I guess that would qualify for your "around 7000" choice, but it seems like people just enjoy exceeding the manufactures recommendation. For now I will do it every 5000 miles just cuz it's free.

mikeb
01-07-2004, 08:32 PM
3k

jerrymac
01-07-2004, 08:41 PM
same here, around 3,000 to 3,500 miles

oi812
01-07-2004, 08:58 PM
First change will be at 2,500 next at 5,000 then every 5,000 after that.

NAVILESRX8
01-07-2004, 09:19 PM
All the rotaries I had, I changed the oil every 2000 miles. This one is going to be no different. Genuine Mazda filters, and Mobil1 0W20.

gingersrus
01-07-2004, 10:40 PM
Reminds me of the old "pay me now or pay me later" commercial. Oil is cheap compared to other things on this car. I am determined to change my old rock and piston habit and check my oil regularly, change every 3K - at the latest.

w2aew
01-07-2004, 10:43 PM
I usually follow the severe duty schedule in each vehicle I have, so that means every 5K for this car. After all, the oil does less (fewer bearings, etc.) in this engine than a conventional engine, so I'm not concerned about 5000 miles (while my conventional engine vehicles get changes every 3000). I did the first change at 1500 though ('cause who knows how long the factory oil's been in there). Genuine Mazda filter and new crush washer on the drain plug each time...

mamccubbin
01-07-2004, 11:04 PM
I figure I'll have it changed every 2500 between myself and the free Mazda service.

Nubo
01-07-2004, 11:28 PM
Only about half of the oil gets changed so I'm planning on 3000mi. I may go with used oil analysis in which case a more objective interval can be obtained over time based on the condition of the oil.

ptiemann
01-08-2004, 01:24 AM
Originally posted by w2aew
After all, the oil does less (fewer bearings, etc.) in this engine than a conventional engine,

hi w2aew, can you elaborate on this? When I check the oil, it looks dirty, so it seems to do _something_.


I too used to change every 3000 m on my Firebird, now I plan on going with the 5000 m interval. Partly because I add fresh oil all the time, maybe that's stupid reasoing.

-Peter

mmmdowning
01-08-2004, 01:16 PM
I change at 1500 due to not all of the oil gets changed.

FirstSpin
01-08-2004, 01:25 PM
I'm going with every 3000 to 3500 miles or so. I've never known for sure about the question posed in the above post but it seems to me to be reasonable. If you add 2 quarts over a 5,000 mile interval (whatever, it sounds like he's buring quite a bit of oil "adding fresh oil all the time") then it would seem that you could go longer between oil changes. Given that the reason for replacing the oil is a breakdown in the lubricity and the rheological properties of the oil, not to get "clean" oil; it seems reasonable that if you're constantly adding fresh oil, you're improving the overall mix in the crankcase.

I'm hesitant to admit this and of course I'd never recommend it to anyone but on my first car, I drove it about 70,000 miles and never once changed the oil. The valves were tapping pretty good by 40,000 and it was drinking a quart of oil every 2,000 miles or so by 60,000. I added oil when the oil-pressure light came on but never thought to change it. The car (a 73 Maverick / slant-six 250 cu in (4.0 liter); ran for seven years and 104,000 miles before it gave up the ghost. The problem that "killed it" wasn't a thrown rod or an otherwise locked-up engine. It simply began stalling at the least convenient times in the worst places and refusing to start again for about 8 hours. No telling how long the engine would have continued running. Like I said, I know it was stupid (so you don't need to post to tell me how dumb it was-unless you just want to). But I thought I'd share the experience just the same.....

w2aew
01-08-2004, 04:01 PM
to ptiemann,

My comment regarding the work that the oil does in the rotary vs. conventional engine refers to the fact that there are fewer moving/sliding parts in the rotary engine. In a conventional engine, you've got main crank bearings, rod bearings, cam bearings, lifters/tappets/followers, valve guides, piston rings, etc. All of these items are lubed by the same 4 or 5 qts of oil. In the rotary, you've got 3.5-4 qts of oil to serve two rotors, apex seals, rotor shaft and associated bearings - that's mainly it. That's a lot less work/qt in my mind. Of course, if you drive it hard, you'll definitely beat up the oil more than if you don't.

Given that my car isn't driven VERY hard, and gets a lot of highway running, I think I'll be pretty comfortable going 5000 between changes. We'll see how I feel about it when I get a look at the condition of the oil at 3000, 3500 etc. (I've only got 2000 on it now, did 1st o/c at 1500).

ptiemann
01-08-2004, 05:54 PM
@w2aew.. thanks, very convincing.

I do a 100 mile commute to work, of which 95 are freeway, so I will stick to 5000 m intervalls.

NAVILESRX8
01-08-2004, 06:29 PM
I just changed my oil for the 1st time. Only 1150 miles on her. The original filter came right off no problem.

On a side note, I realized a big difference in cold cranking with the 0W20 Mobil 1 to whatever 5W20 dino junk the factory put in. Be advised it is like 12 degrees F here in New England. It cranks stronger, and takes a little bit less time to fire up. Also, there is less fluctuation in the cold idle.

MSMAMBA
01-08-2004, 08:26 PM
I will just change it every 3 months even though I do not drive mine too often. Last change was at around 1200 miles along with tranny and differential oil changes.

Since I am sticking with dino oil and the regular change can only change half of the oil, I think I am fine.

Quino
01-09-2004, 11:24 AM
OK - be patient with me - I had an RX7 for 17 years and did al of the oil changes myself - why is it that only "half of the oil" gets changed?

Also - I thought that we should not use synthetic oils in rotary engines.

And lastly - anything magic about the 5W30?

compaddict
01-09-2004, 11:27 AM
I'm doing every 1500 with Redline 5w-20 until the car has 6000 then changing every 3000 after.

Vince

Haze
01-09-2004, 03:20 PM
Originally posted by Quino
OK - be patient with me - I had an RX7 for 17 years and did al of the oil changes myself - why is it that only "half of the oil" gets changed?

Also - I thought that we should not use synthetic oils in rotary engines.

And lastly - anything magic about the 5W30?

1st - It's a seven quart oil system or so, but when you drain the pan only between 3 to four quarts will drain out. The rest of the oil is trapped in the oil coolers, lines and various engine areas. That's why only half of the oil gets changed.

2nd - The manufacturer definitely has recommended not using synthetics. They recommend dinosaur juice because the high ignition temperature which makes synthetics so resistant to thermal breakdown and such a good answer for lubrication, also makes it very hard to burn in the combustion chamber. Since the renesis intentionally injects oil into the combustion chamber, this is a bit of a problem. It can lead to fouling of the ports and plugs with unburned oil, and hydrocarbon.

3rd - The magic number is 5W20 ! Beats me if there is anything magic about it, however, there is a muted threat in the owner's manual that if you switch oil grades from the factory recommended grade and type, it could invalidate your warranty. For North America, 5W20 is recommended for all seasons and types of driving and nothing else is recommended. As pure specualtion, I believe that they are worried about clogging of the emissions control systems by unburnt hydrocarbons, and they don't give a fig about engine wear. However, I'm using it. Motor oil lubricating chemistry has gotten steadily better and better over years of excellent chemical engineering by the oil industry that I don't believe the engine will be adversely effected by the use of a light weight oil. This is a personal opinion based on nothing real, but it keeps me happy. Hope this has been helpful.

Quino
01-09-2004, 04:51 PM
Thaks Haze! I forgot about the oil cooler and lines! I had to replace it in my old '85 because one of the mechanics drove into a ditch or something and cracked it. i didn't noticed until days later when the oil level was low enough that the light came on. - He wouldn't fess up to it - but no one else had driven the car! Anyway - great answer!

zoom44
01-09-2004, 05:13 PM
every 5k miles. on mazda, thank you very much. :)

91vert
01-09-2004, 08:09 PM
You know......I used to be very anal about changing the oil in any car I've owned at 2000-2500 miles. I thought I was doing myself a favor by keeping the engine maintained as best as I could, but I have since changed my way of thinking.

I have recently traded in 1 car and sold another one myself that I had spent hours keeping meticulously maintained and spotlessly clean for the past 4 years since they were brand new. After the grief of getting rid of those cars, I felt like it was a big waste of my time and money. The dealership where we traded the one car in did not even bother to look at the vehicle to see how clean it was and didn't even care about the service records. They quoted us a trade in price and would not move based on the superb mechanical and visual condition of the car. They did not even go near the car until we gave them the keys the day we picked up the new car we bought. The other car that was sold was finally purchased by somebody who seemed to have no interest in knowing that it was well cared for either.

It is frustrating knowing that I busted my ass taking care of those 2 cars so well, and it made absolutely no difference when it came down to getting rid of them. That being the way the deals are made nowdays with the dealerships, I feel like I shouldn't even bother being so disciplined about staying on top of the maintenance, and waxing the car every month. It just doesn't seem worth the hassle in the end.

I guess with the 8 I will probably still be changing my oil around 3000 mile intervals, but if it goes over....I'm not going to stress about it since it won't matter to anyone 3-4 years from now when I get rid of the car except for the new owner......who I won't even know anyway.

If you're planning on keeping the car for many years and trying to put about 300,000 miles on it, then it would be in ones best interest to do an oil change about every 1500-2000 miles.

Arthur
01-11-2004, 08:58 AM
I have a question--do any of you follow the time vs. mileage recommendations out there? I reach the recommended number of months much faster than I meet the miles (e.g., it takes me 6 months to put on 3,000 miles). I know I should drive this car more, but my schedule hasn't been permitting it.

Should I follow the months rather than miles or sort of split the difference?

Doug Green
01-11-2004, 12:00 PM
3000 miles with 0 w 40 mobil 1............no problems lots of rotary powered cars...

80CuIn
01-11-2004, 04:38 PM
Was planning on changing every 5K. Since Mazda recomends every 7.5K, I thought 5K would be well within Mazda's recomendations. But since I'm not using sythetic, I will be changing at every 3K.
Al

Air Force RX8
01-11-2004, 05:23 PM
Had my oil pan replaced at 1700 miles. The service manager said there is no need to replace oil prior to the 7500 interval that Mazda suggests. This is for many reasons he assures me, but mostly due to improvements in oils, less moving parts and therefore less friction caused heat inside the motor. He assures me that this motor can take more abuse than it is given credit for. I will however change at 6K intervals since that is what most oils are made for now anyway.

idle0ne
01-11-2004, 05:34 PM
i will be changing mine around every 3k miles

8_wannabe
01-11-2004, 05:43 PM
I voted 5000 miles since I get free service for the first 50,000. After that, I will do it every 7500 miles. In either case, I'm conforming to manufacturer's recommendation; I feel very comfortable with this.

i3man
01-11-2004, 06:47 PM
I've got about 1000 miles so I'm going to do my 1st oil change this afternoon. I plan to do actually 2 oil changes today because I want to get as much of the old oil out as possible. I'll drain oil and replace filter....run engine a bit....then drain oil again and replace oil. It's also a way for me to test out my new Fumoto valve without having to wait until my next oil change.

rotarymagic
01-11-2004, 08:46 PM
Originally posted by fastrunner
Ok, how many of you guys/gals follow the Mazda guide for oil changes on the 8?


I would never follow any car manufacturers guide for maintenance. I may use it as a reference, nothing more.

rxeightr
01-12-2004, 11:38 PM
I will let the dealership do it at 5,000 mile intervals, and will change it myself every 2,500 miles in-between.

rx8gator
02-07-2004, 05:36 PM
Did my first change today at 1,200. Sounds like every 3K or so afterward is adequate. Whoever put the damn oil filter on at the factory should be shot. It was way too fu#$%g tight. Busted a knuckle good!