Originally Posted By: BrocLuno
Originally Posted By: carock
Is it not significant that there are no racing groups still using conventional dino oils? In an industry where engine tear downs are part of the routine, EVERYBODY has switched to synthetics based on actual observations of wear in the field. My point is that when we look at engines that wear out pretty quickly, synthetics are the obvious choice. There really is no reason to assume that the same thing does not apply to engines that live 200,000+ miles except that it takes so much time to run the experiment. People in the forum have been comparing wear metal results in UOA's and this is simply the wrong tool for the job. Even though race engines may not represent the same duty cycle as street engines, it is a better indicator of oil characteristics than UOA wear metal comparisons.
I have to take exception to the race engine comparison. The oiling systems are not even close. Neither are most of the bearing clearances. Lots of race engines run dry sumps and vacuum pumps to boot. I don't see any on street cars...
Race engines are modified to exclude by-pass valving. 100% of the oil goes through the filter, 100% of the time. It's the only way to prevent 15 micron and bigger sharp hard metal bits from circulating and taking out expensive bearings and valve gear at 7-10,000 RPM. Quicker than you can shut down if you even see a flicker on the oil pressure gage ...
Most race motors I know about have a plate magnet epoxied into the bottom of the pan for the same reason. And valley screens to compartmentalize the valve train from the lower rotating assembly. Valve trains break, and they can do massive damage. Keep them localized if possible.
Non of this happens on street motors ...
And the oils are different. Lots of them are mono-grades up to and including 70 ... Just like pre-heating the tires for some classes, the engine boss often pre-heats the oil before filling the tank. There is no high viscosity cold oil pumping going on. AND, some race motors have pre-oilers to make sure they have pressure before the crank ever turns. I don't know to many street motors that do this ...
If you want to look at motors that get abused regularly, look at fire trucks. Big engines with high reciprocating masses that go from zero stone cold to WOT in seconds and do it time and time again. Some of the locals around here do use Chevron Supreme or Delo which is pretty close to conventional oil (Grp III blend) and those motors last a long time.
They don't like synthetics because they have drain-off issues. The motors may sit for week and then go WOT at 2:00 AM. They like having engines that don't clatter and clack while they are trying to get out the gate with traffic going crazy in all directions. At best they run syn-blends.
Race teams pick synthetics because 1.) they are sponsored and get paid to do so, and 2.) they expect to possibly loose coolant, and they want the lubricant to try to do it's job at 400*F while they are trying to get back to the pits. This is not an assumption that street folks make ...
But I will say that the first ORT to make 1,000,000 miles w/o a tear down was on Chevron Delo 400. Followed by Delvac a few month later. That's documented history. That's not synthetic. So even if synthetics do offer some benefits, they have not been shown to be better at actual lubrication.
AND, even Blackstone among others will explain long and hard how you do not use synthetics in aviation or marine engines until they are thoroughly broken in. Usually not until after the third oil change. There are drawbacks to using synthetics, even though there are sometimes advantages. It depends on the job at hand. There is no one-size-fits-all here ...
There are a lot more race engines that are exactly what you drive on the street, just driven under hard core track conditions. I specialize in vintage race engines. There are hot rodded and tuned engines, and there are four stroke dirt bikes. My experience with these engines is that synthetics are OBVIOUSLY better than dino oils. No dry sumps, no full flow filters, etc. Just like a "regular" engine only tuned with more boost, driven at higher rpm, etc. I look around the pits and nobody is using Delo 400. I am also not aware of any sponsorship deals. It can't just be me who notices this. Also, people who DID have problems with dino oils switched to synthetics, lots of them.
I dealt with general service in high end cars. These are people who have modded Mitsubishi EVO's or 911 Turbo track cars. Everybody has switched to synthetic because they had problems with dino oils. Including Delo 400. These are cars driven on the street.
I was a test engineer for the major manufacturers. They know synthetics work better than dino oils and recommend synthetics when their design highly stressed engines even though there is an extreme bias to keep their Consumer Reports maintenance costs low.And no, the big oil companies are not paying them to recommend their ols, they are cooperating to engineer oils with better performance and recommending the result of their cooperation.
Sorry I can't produce conclusive results showing that your 1996 Toyota Camry would have gone 600,000 miles with synthetics versus 350,000 miles with dino oil. That test takes too dang long. I won't live to see the results.
For all the people who insist that dino oils are just as good or better than synthetics, you need to produce some actual evidence that shows it. Just because a truck can go 1,000,000 miles on dino oil with a 50 gallon sump and a three gallon bypass filter does not mean that synthetics won't outperform the dino oil. Service that is good enough does not mean its the best available. The UOA wear metal results from Blackstone labs are the wrong tool for the job as far as I can see and that is only evidence that is being presented here in support of dino oils. There is no actual evidence in this thread that dino oils out perform synthetics. There is just some evidence that dino oils are good enough to get the job done. Well I am here to tell you that there are plenty of circumstances where dino oils are not good enough to get the job done and synthetics are clearly superior.