SWAT81

iTrader: (14)

Ok, now I need some serious advice on which grade of oil to use for my 3rd Gen RX 1993. The previous owner told me to use 20-50 and I know for a fact this can not be possible since its oil used for heavy duty trucks or vans. Does anyone know what's the best oil for my RX?

1bad7-back

the previous owner was correct. this is due to the fact that the rotary operates at a higher temperature than a piston motor and also the fact that gasoline mixes with the oil in a rotary therefore dilluting it. stick with the 20w50 or 15w50

turbojeff

iTrader: (30)

Dude, if it'll pour into the oil filler neck anything is possible.

Anyway 1bad is right, use 20w-50 unless it is really cold. Fuel does dilute the oil and is normal, the more often you use boost the more often fuel gets in the oil.

Jeff

Ralgh

I know I am just restating what has already been said but Tri Point Engineering also insited 20W50 is the way to go. I have been running it since August with no problem.

FormerPorscheGuy

I go with 20w-50 in the summer and 10w-30 in the winter. FD's have high oil temperatures so the heavier oil is also needed for that. This topic has been debated alot around the forum and is old. Use the search function to find more threads on this.

Joker

mobil 1 15W/50 if you can afford it, motul 300v competition oil ($13-per-liter)...good stuff!

93blackrx

wow I didn't know that, what should I use when breaking in my engine? I know I should search but I'm a lazy slob. I know I should use dino oil when breaking in but what weight?

Matt

Joker

use whatever oil you plan to use during the life of the motor and turbos.

for me that's mobil 1 15W/50

93blackrx

cool thats what I'll go with, Thanks.

Matt

Nameless

Break in your motor with dino oil. 20w50, breaking in with synthetic is not advisable cuz of glazing.

adam c

iTrader: (2)

Pineapple racing also recommends using Mobil One synthetic oil. I use 15/50.

Adam

FDjunkie

When I used 20w-50 Valvoline my high RPM oil pressure was much higher (maxed the gauge even once fully warmed up) and the engine burned significantly more oil. You could easily see a big cloud of bluish oil smoke behind the car anytime I accelerated hard. I now use 10w-40 Valvoline and just keep it changed regularly.

On a related note, I found that the higher oil presure also contributed to the oil pressure sender failures. https://www.rx7club.com/forum/showth...hreadid=124078

SleepR1

Glazing? What is that? Is that burned up oil deposits?

Mobil 1 has a bp of over 300 F! The higher boiling point means it will not burn up and leave "glaze" deposits?

93BlackFD

i am running 10w-30...should i switch? live in georgia and temp rarely goes below 30F this time of year

Joker

10w/40 or 15w/50

Nameless

I'm just giving it to you as Tripoint and Mazdatrix has told me. If they are feeding me bullshit, then so be it.

SleepR1

Oh, ok differing opinion

I'm giving the opinion Dave Barninger of KD Rotary gave me

Maybe it's all

Nameless

maybe

SWAT81

iTrader: (14)

So overall Mobil 1 10W-30 is the best choice? By the way my RX has 65k miles on it and when its on idle it smokes alot but after 5mins it goes away. Is this normal? Its white smoke but sometimes it had a slight bluish tint. A mechanic friend told me it doesn't smell like oil or coolant so I have no clue why its doing it.

Rx-7$4$me

if its cold where u live, it could just be normal moisture since the exhaust heats up so fast from rotarys