10/30w or 20/50w
 

I have a 87 T2 just rebuilt with street port, so when im done breaking in the motor which oil weight should i use...for mineral oil should i use 10/30w or 20/50w and if i use synthetic which weight should i use. Also thinking about going premix so i can use synthetic...

search 'oil' and get a shit-load of info. i use 20w50 castrol gtx, but i dont recomend using synthetic, though people say it is fine, the motor was not designed for it, so i stay away from it.

NO SYNTHETICS. Mineral oil only, I use Castrol GTX 20- 50

Ok, a slight sidebar to this question... I've got a higher mileage 87 n/a that's in pretty decent shape. No mods, YET... I've started started using "High Mileage" oils... Is this ok?

You should use 20-50 in the summer and 10-30 in the winter... And some synthetics are ok... When Mazda put the warning out about not using synthetics, the quality of synthetic oil wasn't what it is today... I still don't use it though... lol

Not a problem with high mileage oil...

Castrol GTX 20W50

:)

Wow we've been through this many times...

1030 in the cold 2050 in the summer for mineral

as for synthetic, Mazda recommended against it becuase there are only some types of synthetics that would work with the rotary, only the very high quality ones (mobil1, MMO etc), whereas the lower grade synthetics (castrol) would leave ash deposits when burned.

if the MOP is removed, any oil can be used in the crankcase because it is no longer being burned. Basically any TC3 2 stroke oil will work fine for the premix.

think ive got that right :P

very good detail answer jono20

thanks very informative

"High milage" oils are loaded with additives. Avoid using them.

FWIW, I use Castrol GTX 20W50 in my 170-something thousand mile, stock engine N/A (along with Honda PCX "S2000" filters.)

Castrol 20W50 :bigthumb:

Actually I think the manual says 20W50 for anything over 80 degrees and 10W30 below that. I can't remember what the lower temp range was. Hell (sometimes I think thats where I live it's so hot), we are almost always at 80 or above except for a month or two out of the year!!! I had to flip out on the local Mazda dealer when he put 5W20 in mine. I was like, "Hey, don't you guys have a service manual you are the Mazda dealer? If you don't I can bring you a copy!!!!" "Huh, no your car is too old." "Hello!!!! Not to mention I told your "Service Manager" I wanted 20W50." I got my money back and went and had it changed at the normal place I go. When they drained the oil it was like water it flowed so easy!!!! I guess as the old saying goes "If you want it done right you have to do it yourself" I guess I've just gotten lazy in my old age. :D

Hmm, the climate in Ohio is a bit cooler that in Richmond... I may have to run 10/30 in the winter.

its 5 quarts of oil right?
For some reason i just use 4 and its full on the dip stick

4.5 if I remember correctly...

I used 10W-30 Mobil1 Full Synth at my last oil change, the only difference I saw was my oil pressure rising about 3psi from looked like 27 to 31 at idle and 57 to 61, also used a K&N Oil Filter...

- Tech

mazda did not recomend the use of synthetics yet they ran synthetics in there own race cars

how ironic

as long as you premix and take your omp out i hear synthetic is no problem

You have to account for the filter too... ;)

as I said, high end synthetics work wonderfully. it is the lower end ones that result in probles after combustion

Yep, Mobil1 with no extra additives (high mileage, etc) for me...

Mazda also ran premix, and was not injecting crankcase oil into the intake like the street cars do. As posted above, with no MOP, what you put in the crankcase doesn't matter (as to how burnable it is).

Regarding oil change amounts, the system, totally dry, takes 6 or so quarts. However, when you change the oil, not all of it gets out, mostly due to the oil cooler and lines.

What I've found makes a big difference (5 quarts vs 4 quarts at a change) is having the engine really hot when you change the oil. Not burning yourself can be a bit of a trick, but I always take the car for a good hard spin right before I change the oil. The hot oil flows better, and you get more of it out.

-=Russ=-

i use castrol gtx 20/50 non synthetic.

im thinking of trying to start taking this !!! special oil for rotary !!

http://www.idemitsu-usa.com/page_211.htm

ROTARY LUBRICANTS

These formulations have been specifically engineered to meet the unique requirements of a rotary engine. The technology base for these formulations goes back to the first and only 24 Hour Le Mans race winner using a rotary engine for which IDEMITSU developed the winning oil.