want.turboII.S5

Ok so its been about 5k miles since my last oil change, and thats when it says i should get another one according to the sticker they put on wind shield last time i got one. but ive been adding oil the whole time since then because it burns it. if i take it in now they will be taking out almost a quart of new oil. how often should i be getting oil changes? i drive about 50/50 highway/normal roads if that matters and couple times a week i drive it pretty hard. any reply appreciated

RotaryEvolution

iTrader: (30)

5k miles? did you get a piston engine conversion?

keep that up and you'll never get the oil to come out any color besides black.

3k is a typical rotary oil change schedule and even that can be high if your oil is coming out dirty or smelling of fuel depending on various circumstances.




if you are concerned about losing a quart of oil, maybe go buy a hybrid. my hybrid doesn't use any oil and i don't need to change the oil for 12.5k miles, it's also slow and not fun to drive.

thing about only adding oil and never changing it is that all the pollutants still collect in your oil pan and just become more concentrated if you don't drain them out. those pollutants promote wear.

want.turboII.S5

im not "concerned about losing a quart of oil", just wondering how it effects how often i should change it. simply went by what the "car professional" put on the sticker. inherited the car and still learning.

thanks anyways guy

RotaryEvolution

iTrader: (30)

every 3000 miles, adding oil doesn't affect that.

Evil Aviator

It depends how you drive your car. If you drive aggressively or autocross the car, only drive the car on occasion, or primarily take very short trips (about 10 mi or less), then 3,000 miles is a good time to change the oil. High-mileage engines may also need a 3,000 mile oil change. However, if the engine is in good shape, you drive the car often, and mostly take long trips (20 mi or more), then 5,000 miles should be fine for an oil change interval. Whatever you do, make sure you change the oil at least every 6 months, even if you do not hit the above mileage gates.

As indicated in the previous post, adding oil is a separate issue. The oil needs to be added because the rotary engine burns about 1 qt every 3,000 miles as part of its normal operating cycle. If you are lazy like me, rather than adding an extra quart at 3,000 miles and changing the oil at 5,000 miles, you can simply just change the oil at 3,000 miles and be done with it. However, still check your oil level periodically because if your engine is burning more than 1 qt per 3,000 miles then the engine is due for a rebuild.

Sgtblue

iTrader: (16)

+1 for about 3k interval. Rotary engines tend toward at least some fuel dilution. This is especially true if they're running rich or, like you, operated in cold weather where cold starts necessitate rich mixtures.

Evil Aviator

This, and the eccentric shaft tends to shear the oil. Fortunately, as technology progresses, oil is becoming more resistant to shearing, and is also a lot better at keeping the fuel and other contaminants in suspension. I don't think that oil changes are as vital today as they were back in the 1980s.

horvik3

I change mine every 5000kms/3000miles I do alot of highway driving and quite abit of track days so kinda thought the low load highway would balance out the trackdays

Sgtblue

iTrader: (16)

The other thing not previously mentioned is that I live in the Midwest and the car is stored for half the year, and not daily driven during the other half. Changing every 3k, or so, means the difference in one oil change per year...or about $30. As a percentage of total money pissed away on cars of mine it wouldn't even equal one hair in Trump's total comb-over.

emkaysix

One thing I miss from my old GTI, change the oil every 15k and be done with it. Every 3k means I'll be getting real familiar with the car whether i like it or not...although thats not such a bad thing

lonewolf676

I'd say every 3,000 miles to stay on the safe side. It's an engine design for it to burn through oil, so I'd think it's better to get more frequent oil changes than needing to replace a damaged motor imo.

Nabu

Not exactly following the topic but grabbing from this post above i had the following question.

Are rotary engines any different when it comes to lubrication than piston engines?

Every time i was having a full day trackday with more than 6-7 hard sessions during the day i used to change the oil and brake fluids after.

Especially when used some specific oils such as the Motul V300, i experienced serious change in the oils characteristics.

The oil started to be consumed very rapidly after some sessions whereas this was not the case for previous road use or the first sessions of the day.

It is like it reaches its peak operating temperature and from that point on, it starts fading as far as duration goes.

Car was a Honda S2000, so it was a high revving engine.

Any trackday users around here that would like to shed some light?

Thanks,
Konstantinos.

wayne harper

I have a related question. I have not changed my oil in over a year. I have a 1988 Turbo but I don't drive it regularly -- couple times a month. In fact in the past 12 months, I put on about 200 miles. The oil is not black, and I have not added any new oil. So, what's the shelf life of oil?

Sgtblue

iTrader: (16)

As I understand it, condensation can still take place inside the engine and not be naturally purged by bringing the car up to temperature. Also corrosion inhibitors and viscosity modifiers can break down with time. As a part of the total cost of keeping just a pleasure car, oil changes pretty minor. Not likely any real damage is done but I'd change it and the filter before the next drive.

fc3sfc

I do 3k or 3months

Evil Aviator

Once the oil is put into the engine, the color is not an indicator of the quality of the oil. This is because the oil keeps contaminants in suspension, and most of the coloration you see is not affecting the oil or the engine. If you truly want to know the quality of the oil then you need to send a sample out for testing.

Motor oil will generally stay good indefinitely if stored in a sealed container in a controlled environment, although most companies recommend a 5-year shelf life for their products sealed in the standard container stored in a typical garage environment. Oil subjected to extreme heat or freezing cold will probably degrade prior to the 5-year mark. Once you put motor oil in your engine, it will stay good for about 6 months before the acid starts to get to significant levels.

Driving your car infrequently is actually bad for the oil, as well for many other components of the car.

wayne harper

Thanks for the info on the 5-yr self life of oil. And I know the value of driving my RX7, but it's no longer my primary vehicle.
When I was in the Air Force we had a name for an aircraft stuck in maintenance -- 'hangar queen'. I'm trying to prevent
this becoming a reality with my RX7. I suppose it's time for an oil change. Thanks again. Wayne

Wouter Bollen

Every 3k Miles...

Evil Aviator

I was once attached to a unit with a UH-60 hangar queen that was an old NASA testbed that some idiot maintenance officer accepted without noticing that it had tons of Frankenstein wires and sensors wired into everything making it unairworthy and impractical to repair, lol.

So if the car is driven 200 miles each year, then you suggest an oil change every 15 years?

Sgtblue

iTrader: (16)

IMO it's harder on your car sitting like that than being driven a few thousand miles. Gremlins seem to breed like rabbits. Probable the same with aircraft.


Have to build up that post count somehow.

regaul2

Agree with everyone else regarding every 3,000. I have disconnected the oil metering pump (is was leaking and did not work anyway), so now I have been premixing every time I fill up the gas tank.

Evil Aviator

It's even worse with aircraft. For one thing, aviation engine oil does not contain any detergents.

That's the only reason I post in here. I think about 15K of my posts got lost in the various website crashes and mass-deleted threads, so I am trying to rebuild my post-count so the Millennials think I'm cool.

Brandon Jessup

personally on my old fcs i would do no more than 2500.
but since i have access to a lift and cheaper parts i kinda stopped counting and do it every other month. but i always daily my rotaries.

Truenogts88

What kind of oil brand are you guys running and what kind of oil filter too?

Evil Aviator

Castrol GTX oil and the OEM Mazda oil filter are the most commonly-used brands. However, any of the major brands should work fine. I am not aware of anything that is bad. See the factory service manual for the proper oil viscosity for the temperature range in your area.