13B S4 NA motor 70,000 miles

Now, I'm approaching the 2500 mile mark since last Oil change...
Is there a brand of Oil out there that is cheap and works well for rotary engines? I know no synthetic..

Octane 87 seems bad, looking for something that is just right for the engine as well.

 

search

 

castrol gtx 20-50

thats what recommended

i love it when noobs tell other noobs to search

 

Use a good quality oil. Most folks around here recommend Castrol. 10W-30 during winter and 20W-50 in the summer. Synthetics are OK as long as you use a full synthetic (no blends) and a high quality one. Check the oil level at every gas stop. Rotaries don't take kindly to low oil levels.

87 Octane is recommended for N/A's . Actually, there is no benefit to be gained from using a higher octane. I would recommend using Texaco, Chevron or Shell.

 

as for conventional oil I would use as stated 20w50 summer and 10w30 winter Castrol GTX..

IF you are going to use Synthetic oil ELF is the oil oil that is approved by Mazda to be used in the RX8 (no synthetic oil was ever approved for the RX7). However they dont carry a 20w50 or a 10w30 I use the 15w50 however if u still have the omp installed ELF recomends (as does mazda) you use the SXR 5w30 oil ONLY

as for gas stay with 86, and I use either Mobil, BP, Texaco

 

That "noob" has been a member longer than you

 

Stick with 87 octane on a N/A FC unless you are running crazy timing. Because of the elongated shape of the combustion chamber 87 octane's quicker burn is an advantage.

 

i stick to castrol...i try royal purple once and i suffer a blown apex seal. but that just my luck. i use the cheapest gas station i can find. that just me since mine is not turbo but i mostly use am pm.

 

All right, I'm going to stick my neck out here...Upon recommendation of my mechanic, which was confirmed in the original owner's manual (amazingly still pristine- found in glovebox), Mazda recommends 5/30 in the winter and 10/30 for more extreme temps.
NOWHERE do they say anything about 20/50.

I'm partway through my vacation trip and prior to leaving I did an oil change...admittedly with trepidation...and used 10/30 Castrol GTX.
Drove straight from Denver to Chicago, almost exactly 1000 miles, in just under 14 hours, in 100 degree weather.
Oil pressure/temp were fine, consumption was normal (for my worn engine at least)- I added 1/2 qt.
So far, the tendency of the car to blow occasional clouds of smoke has completely ceased as well, but it's too early to draw any conclusions about that.

Mileage was surprisingly good as well...for the 1000 miles I averaged just under 29MPG (with constant AC usage).

Make of this what you will but it's worth considering.

 

I guess it's too late for me to be careful joining the debate...

I've used almost always Castrol GTX but tried Quaker state 10W30 this time around because I read some posts about some oil analysis here regarding deposits and such (after searching). My ambient temp. range is within this, looking at the chart. I use this year around. I figure as long as you follow the chart, there are probably worse sins we're committing on our cars.

I prefer dark haired, exotic women myself.

 

Oh joy, another oil topic...

On the subject of 20/50 vs. 10/30, I don't personally believe that Mazda's recommendations are what's best for the engine.

In Ontario Canada where I live, temperature swings from -40 to + 40 (and sometimes a little higher). In the winter, 10/30 has always been fine in any of my RX-7s. Pours easily, no real pressure issues, and comes up to temp quickly.

In the summer however, it turns to water once the engine warms up. Oil pressure drastically drops and consumption goes way up. If you flood the car, the oil becomes very thin and I question how much protection it offers at high engine loads.

20/50 is almost solid at low temperatures so for winter driving it's not an option. But once the weather warms up it thins quite a bit. Oil pressure is noticeably higher at all RPMs and during changes it's easy to tell that it's not thinning out like the 10/30. Also oil temps seem better, but that just may be a function of the brand.

As for brands, I buy whatever is on sale. Generally this means Canadian Tire "Formula" 20/50. Synthetic is quite expensive and I don't see the benefit...

With that said, oil topics are the 2nd most common topic here besides "how do I turbo my NA?". Oil is well covered in the FAQ, and a simple search for "oil recommendations" or "oil type" or variations on that theme will turn up the thousands of multi-page threads that already exist.

 

The debate seems to continue because Mazda gives contadictory advice.
The owner's maual recommends 5 or 10/30 but the FSM also includes 10/40 and 20/50.
Who (or what) is a boy supposed to believe?