well dont know if anyone else on here has tried this, but today i changed the oil in my car, my usual K&N Gold filter, and today i went with 10w-40 Castrol GTX High Mileage oil, now, does anyone have any stories or pro's and con's to high mileage oil in a rotary?? let me know, im a pioneer lol

 

I believe thats a bad blend for rotaries. Someone else will prolly tell you more if it is. Can't remember really though, sorry.

 

IIRC the high mileage oils have addatives that may gum up the internals of our engine. The addatives are made to "plug up" areas on pisston engines that leak, or give overall higher mileage feeling to them. Something to do with the oil rings in them? I can't remember and I can't find the article that I read it in. Hell I can't even remember what magazine it was in LOL. I still use Castrol GTX in 10W30 on my vert...since August of 1991

 

well typically 10W40 and 10W50 oils already have a considerable additive package just to get that viscosity break, and are for the most part not recommended on modern high temp and high reving motors. Some manufactures (like Toyota) have been even refuseing to warrenty some engines in parts of the country that 10W40 or 10W50 oils are used in as they have found considerable build up, even when the oil is changed every 3000 miles.

Is there a reason that you are using that viscosity? are you expecting temps between 10F and 70F??? normally 20W50 is recommended for rotaries operating in the 20F up temp range.

 

lol, whoops, well my engine has 180k on it, so if it goes it was time lol, guess ill just switch back to the normal Castrol GTX after 1500 miles lol, i change every 1500 anywyas

 

flush it!!

 

I use 10-30 and im in south CA. The temp is usually above 45degrees. Dont you think going to something like 20-50 is a little to thick?

 

No, 20W50 will give you more protection than 10W30 (which really shouldn't be used in a rotary used above 70F).

 

Well temps here hit low 60's during the night. I know it'll give more protection but do you think its a little too thick and might be overkill? But then again considering rotary's run hotter then conv. piston engines it may be the smarter choice Im just worried that 20-50 may be too much and just drain power.

 

I recently started using 10W40 in my car because the FSM said it was suitable for a much wider ambient temperature range than 10W30 was. I live in Portland Oregon, and while it does freeze in the winter, I don't think it gets as cold as the lower end of that temp. range, and it gets hell shot in the summer. Not like Arizona and CA, but it'll beat 90-100 any day in the middle of summer. If anyone has an opinion on my reasoning (preferably one lacking profanity), let me know.

 

Okay, here it is again (man, no wonder there are so many dead rotaries out there).

Oil temps and break downs:
5W30 - only to be used under 30F
10W30- -10F to 80F
20W50 - 20F to 140F

As a last resort:
10W40 - -10F to 100F
10W50 - -10F to 140F

Odd viscosities like:
15W50 - 0F to 140F

But again please read up on 10W40 and 10W50 oils before using them. They will have increased deposits in a rotary or any other high reving engine. While they may be fine for your Dads old push rod Chevy, the additives needed to be dumped into the oil will increase both ash content (whats left when the oil is burned) and sludge.

Please read this link before using 10W40 oils in your motor: http://www.vtr.org/maintain/oil-overview.html as it is just one of hundreds of reports saying the same thing.

And if you put too low of a viscosity oil in the oil will fail to protect your motor... for example using a 10W30 and you are driving around when its 90F-100F outside and the oil is breaking down and is not a thick enough layer on the contact parts to protect the engine. This will not gain you any HP when metal starts rubbing against metal with too thin of a shear level to the oil.

 

what about single weight oils, like 30 wt, etc?

Also, I know a few TII guys who run 15W 40. is that still too much of a split?

 

15W40 would be much like 20W50 as far as the split, and should be safe up to around 100-120F

I would have to get back to you on the 30W, as I know Mazda doesn't recommend single wieght oils.

 

Bah, you guys make way to much out of nothing.. I am running castrol 20-50 High Mileage oil in my N/A with a mobil 1 filter. The cars runs flawless with 201,000 miles on the original motor. I have been running that same oil on that car for at least the last 15k miles.

I plan to run the grey bottle 20-50 Castrol syntec Semi-Synthetic on my 10AE's new motor as soon as the break in is done. And I will run regular 20-50 castrol during the break in. I don't care what anyone says... the reason you don't run any kind of synthetic in a engine during the break in is; It does not break in properly... that that MUST mean it prevents wear. Preventing wear is a good thing in ANY engine!

 

However I do recomend only using 20-50 based oil .. i think the heavier weight oil is the only way to go. But I am of the opinion the any addatives are aplus .. synthetic, semi synthetic, high mileage, Etc.

 

first impressions are in

ok first off i would like to say i recommend this to ANYONE who has failing corner seals, mine were failing and even an ATF treatment wouldnt help, it would puff out lots of smoke if i drove above 5000rpm for more than a second or so, and it would shoot out a big cloud if i shifted above 5000 and it wouldnt pull past 6200.

after the oil change it does not puff smoke even driving over 5000rpm for about 30-40 seconds, it doesnt puff out any smoke on a shift over 5000 and i can now shift at 7000rpm.

those are my impressions so far, my engine has 180k miles, and the Castrol High mileage says it breaks down carbon deposits, seems to be working good now, only been in the car for about 25-50 miles, i have nothing but praises so far