Hey guys,


Im due for an oil change, and am wondering which Dino oil you guys have had the best sucess with.
Im currently running Castrol Syntec 5w20, and want ot make the switch to a dino oil.



Let me know what you think!


-bindon

 

The new mobil1 5000 is pretty awesome. Its a heavily refined Group III oil. Pretty bad *** basestocks. Its actually considered a syn by some "other" oil companies, but technically its just seriously refined dino oil.

 

Stick with what you can get, I say Valvoline. Always rated High and nobody ever complains about it.

Great,
Jeff B.

 

mobil 1 5000 5-30w. yes 5w-30 for us southeners. Car sure sounds better
olddragger

 

Castrol GTX 5w20 works for me.

 

good old Castrol GTX is excellent, there's a reason while all other oil makers keep putting 'New!', 'Improved!' labels on their dino oil offerings, Castrol just keeps chugging along with the GTX. Castrol knows dino oil formulation :D

 

that said, i may try out the new Mobil Clean 5000 dino oil, Group III oil at Group II/I price!

 

Similar question from a new guy: The manual says 5W-20. Isn't 5W-30 at least as good. Why does the manual seem to insist on 5W-20?

 

Castrol GTX as well here.

 

5W-20 is mainly used to improve fuel efficiency, that's why most new cars today are specifying 5W-20.

also, most 5W-20 oil available today also passes very stringent Ford and Honda 5W-20 oil requirements, so the 20 weight oil grade should not be a problem.

I stick with 5W-20 because a) it's what the manual says to use, and b) there are some *really* good 5w20 oil out there, why not use the latest and the greatest :D

 

Castrol Syntec 5W20 is a 'dino' oil.

It is hydrotreated, so they claim that equals synthetic - it doesn't.

My refinery is actually called a synthetic crude refinery, because all it's feed is made in the oilsands, not pumped up like "dino".We hydrotreat over 100,000 barrels of oil per day, but none of it qualifies, in my opinion, as 'synthetic'.

Just pick a big-name 5W20 like the book says.

S :D

 

stealth is very much correct. Syntec has dino base stock. Mobil One Synthetic is a true synthetic.

 

Don't know why does the manual say 5W-20 but I heard in Europe the spec says 5W-30. The 5w-30 should be just fine.
There is no reason to freak out like several people did if 5W-30 is used by the dealer. Sure they should stick to what the manual recommends but there won't be any harm done.

 

The problem with dealers putting in different oils then the manual specifies isn't with the oils...its the fact the dealer isn't following manufacturer guidelines.

If they can't get the oil viscosity right, what else are they screwing up?

 

despite some postings of earlier Mazda literature, my 2005 RX-8 Factory Workshop Manual states 5W20 for all markets, the only difference is in the oil spec designations

ILSAC for US/Can, ILSAC/API for non-US

nowhere does it mention synthetic vs dyno preferences or warnings, same for alternate oil weights

edit: that's not to say there isn't a bulletin stating otherwise, but you'd think they'd have it right by the time the 2005 manual was printed

 

You have a good point there

 

All I know is since i have switched to 5w-30(mobil 1 dino) my start ups are quieter and the engine in general is smoother/quieter. No performace lost
olddragger

 

Castrol GTX 5w-20 for me too. Loaded up on it as it was on sale recently.

 

For dino oils I like Castrol and Havoline only. Both of those oils are formulated very closely to each other. They do not contain quite as many additives as the other oils and generally (unless they have been reformulated and I don't know it) have lower ash content which leads to less carbon buildup.

For sythetics I like Royal Purple, and Amsoil for their good stability and low ash.

The lower number in an oil such as 5W20 is the weight of the oil. In this case it is 5. The higher number (20) is what the oil behaves like when hot. To do this the additives do some weird stuff and bond together in longer molecular strings. The farther the high number from the low number, the longer these strings. Don't necessarily think this is a good thing. The best thing is an oil that maintains or stays very close to it's original weight. They are more stable and have less potential to break down. I personally use straight 30W dino oil when breaking in an engine due to it's consistency. 5W20 is a gap of 15 . 5W30 is a gap of 25. The 5W30 oil has longer molecular bonds and I don't like this. Just remember that all of these oils protect equally well and outside temperature has nothing to do with it since the engine is hot regardless of what the outside temperature is.

Valvoline??? Someone is going to use an oil in a rotary engine that is named after an engine part we don't even have? Wow that's scary!!!

 

you might as well of asked what color people prefer :p

as a 45 yr old gearhead-mechanical engineer-racer it never ceases to amaze me how much people continue to over-****-ize motor oil Bobistheoilguy is a perfect example of how to capatilize on people's fears and beliefs, as are all the conditioners, additives, and now marketing schlock from the oil manufacturers themselves who have come to realize they can capitalize on the value-added mentality too.

Just get any general brand oil in the general recommended viscosity range and follow the general maintenance schedule and you won't have any problem. It really is that simple

 

I personaly feel that a low ash oil is the only alternative in the rotary as we inject it into the combustion chamber. Carbon buildup can be a bad thing in a rotary. Check out some of the auto stories of carbon lock and engine replacements from carbon buildup.

 

well looks like i'm gonna be going back to the Castrol camp for a while, just picked up a case of Castrol GTX 5w-20 for $17 at Advance Auto (Advance Auto has a sale til Fathers Day on Castrol GTX for $1.48 per quart)

thanks rotarygod for reminding me of the ash issue, as that is quite relevant to rotary engines, hence why Castrol got my money this time around

picked up 3 Purolator PureOne filters at the same time too :D

 

When I went to the store, all they had for 5w20 was Valvoline. So thats what I got. Should I be concerned now and find Castrol somewhere immediately, or finish the Valvoline and then move to Castrol?

 

Your car isn't going to die or anything from using Valvoline. Don't worry about it. I'm just very strict in what I personally like and use. I only use Wix oil filters. We need our own oil line for rotaries (yes I know about Idemitsu) called rotoroline just to be fair.