I have been 10w30 mobil 1 in my car for a while
kinda curious about using a thinner weight oil though
something like 0w20 or 5w20
I'm just curious on if this is going to be too thin of an oil for my N/A car

and please don't turn this into a don't use synthetic in your car you will blow it up thread that's not the point unless you have HARD PROOF that it ruins motors.
I'm curious only about if this weight is going to be too thin

 

0W-20 and 5W-20 are primarily for European cars and 4-cylinders. (My mom's Honda Accord reccommends 5-20) I wouldn't try using these on a rotary because I'd be afraid that the engine would burn them up faster than thicker weight oils. what made you want to try this?

 

i use 5w30 in my car

 

To quote the drummer. "Light wight oil...Baaaaaaaad."

 

hahaha... Stupid Lars.

 

I use 20w50 in my car.

Personally I would be afraid that the oil wouldn't be thick enough to do it's job properly or something along those lines. I would stick with 10w30 if you like thin weights.

 

I run a 5W50 synthetic so that it's both thin on start up and thick enough to handle the heat of serious abuse. There's no question that on startup the engine his noticably happier with a thinner first number.

Does anyone know what the Renesis runs on? :p 5W20. (I'm not recommending you run that on your FC engine)

 

I used to use 15w40 but now I use 20w50... I'd use thicker if I could but it's hard to find! unless i use like gear oil or something... HMMM

 

Thicker is probably better due to the design of our bearings, especially as they're getting older and clearances aren't what they used to be...Thinner oils might result in some unwanted bearing to e-shaft contact, which is why I can't believe some of you guys run MMO in your lubrication systems- that stuff is REALLY thin

 

Gotta love the peppermint smell of the exhaust though

 

Ya i bet its a nice change from the usual sea-doo smelling, eye burning fumes we're used to.

 

No joke, if I stand behind my car for more than 10 seconds my eyes burn

 

i use 20W-50. when i bought my cat the dealer told me he had just put some 10W-30 and my engine burned that oil right up. i really dont have any problems when i use 20W-50.

 

Actaully, a lot of car manufacturers are going with 5w-20. The rx-8 also uses 5w-20.

 

5W or lower oils on start ups with temps above 0F are way to thin to provide sufficent shear strength on the tollerances of our motors. As well as then you have the problems of cold seal blow by leakage (a problem only when cold).

Using that lightweight of an oil will result in increased engine wear on a 84-96 13B start up.

In addition, the additives needed to get a 0W50 or even a 10W40 viscosity range will tend to burn and leave increased deposits, and while this is probably not an issue for Synthetics, it would be a major issue for build up in the internal moving parts on a conventional oil.

 

**** i think i have to do a oil change now

 

 

20w-50 all the way. that many happy rotor heads cant be wrong.

seriously, general consesous among the old salts and experienced mechanics on this forum is to use 20-50 all year unless you live in the north (or other climate that drops below freezing consistently) then go with 10-30.

also, the one time i used 10-30 oil pressure at low rpm was significantly lower (like at 25-30 instead of 45psi) than with the 20-50. you might not even have pressure with an 0 weight. hell, you might as well lube he damn thig with kerosene if you are gona go that light.

 

would using a syn oil change the possible weight at all

 

damn.. i thought i was being safe when i bought 4 quarts of 10w-40. i live in hawaii, am i alright with this oil?

 

What kinda idiotic statement is this?
Do a search under my nick and synth oils.
We've found Amsoil 20W50 left deposits on the rotor housings that cause the apex seals to chatter.
This cannot be a good thing.
Therefore I do not recommend using them, unless YOU have hard proof your synth oil is not doing this.
http://fc3spro.com/TECH/FAQ/synth.html

As for running this oil...why do you care?
Are you looking for the 1hp gain from the thinner oil?
Mazda has a posted graph of what is recommended due to your climate.
Is there a problem following their recommendations?

There is no reason to go to synthetics.
Are you running turbo?
If not, it's a waste of money for an NA.
On a turbo, it's recommended if you're running pre-mix and no OMP.


-Ted

 

It's alright.


-Ted

 

The newer SG & SH formulations give more latitude that we had back in '89.
I use 10w-40 in my ~40K engine, in Florida.
I'll switch to 20w-50 around 90K.

 

Can you please be more specific? The additives that are used to modify the viscosity on multigrade oils are different for polyalpha olefin based oils and polyol ester based oils. These additives are all long polymer chains, and as far as I knew, the only downside to using them was shear strength loss. This was due to shear forces actually breaking the long polymers into shorter molecular chains, or when the polymers would align themselves to create a path of least resistance.

I have read in other places that it is bad to used 10W40 and 0W50 oil in rotaries, but I havent gotten a good answer as to why. And just like the "synthetic is bad for rotaries" argument, I refuse to believe it unless I understand exactly what is going on.

 

Why would you want to try lighter weight oils? Just use what Mazda recommends...they did far more research than we have. I think they know whats best.

-Joe