We separate fact from fiction with some of these more common—and harmful—oil myths
By Jeff Huneycutt
We live in a world where more is better. More money in the bank account, more friends in the Facebook account, we even know some people with more tattoos than we care to count. But among all types, horsepower freaks and gearheads may be the worst. When it comes to horsepower more is never enough, even if it means sacrificing durability and drivability.
If that describes you, we’re not here to judge. After all, we’ve been guilty of giving in to horsepower gluttony ourselves (more than once). But we think we can help you with a few ways to gain horsepower while adding durability, too.
A big part of Driven Racing Oil’s Lake Speed Jr’s job is to help engine builders, racers and even everyday gearheads find the right lubricants that will help improve their rides. Lake says many of the mistakes he sees people make are because of a lack of good information available. Without it people are forced to depend on what they think they know, the occasional urban legend and advice from friends—but who knows where they are getting their information from? Lots of times it comes down to commonly believed myths and with little based on real facts. Here are a few myths we hope to help you avoid in the future.
The “Viscosity Equals Protection” Myth
Many gearheads use motor oil viscosities higher than necessary simply because it is what they’ve always used. But engine technology and components are constantly evolving, and motor oils have evolved along with them. Because of advanced chemistry, a modern engine oil can provide superior protection even at lighter weight viscosities, and that lower viscosity helps free up some horsepower because the oil pump doesn’t have to work as hard to move the oil throughout the engine.
“But I’ve got a lot invested in my ride,” you say. “I’m more concerned with maximizing longevity than squeezing out every last ounce of horsepower. Wouldn’t I be better off still running a modern synthetic oil with a higher viscosity?” The answer is probably not.
The myth of improving protection by increasing viscosity can actually be harmful to your engine in some circumstances. As much as 70 percent of the wear on an engine occurs at start up. That’s because while the engine has been off, the oil has an opportunity to drain back into the pan and away from the areas it needs to be. Obviously, you want to get oil back to the bearings, the cylinder walls and all the way up to the valve train as quickly as possible to bring the protection back where it should be.
So while a thicker, higher viscosity oil does usually provide a stronger film surface to protect the bearings, that only applies once the oil is in place and ready to do its job. But thicker oil is more resistant to flow, and it takes longer for the oil pump to push it through the oil galleries to where it needs to be. A thinner, lower viscosity oil flows more easily right at startup and gets to those critical areas more quickly. Because of that, a thinner oil can actually do a great job of reducing the wear an engine sees when it is first cranked.
But that’s not the only way the myth of more viscosity can hurt both your engine’s performance and protection. The oil’s viscosity must be properly matched to the components in order for both to work their best. “One of the easier and more popular ways to make more horsepower in modern engines is to use lightweight, thinner piston rings that have less tension between the ring and the wall of the cylinder bore,” Speed explains.
“If you use a motor oil that’s too thick for the application,” he continues, “one of the problems you can run into is those low-tension rings won’t be able to properly wipe the cylinder wall and too much oil will find its way into the combustion chamber.”
So the obvious question becomes how thick is too thick? Or, how thin is too thin? After much research, Speed says a good rule of thumb is to monitor the oil pressure at idle when the engine is up to operating temperature. Consider 20 pounds of hot oil pressure at idle to be a safe minimum, so start with your usual oil viscosity and lower the viscosity at each oil change until you get to 25 or 30 pounds idle pressure. Just make sure you use a high-quality oil that won’t lose film strength under normal operating temperatures.
The “More Additives” Myth
Another common myth is that since most high priced “performance” oils advertise their super deluxe additives, and many companies are even selling bottles of motor oil additives to add to whatever oil you like, then more additives are always better. You’d better believe this isn’t true. Additives have to be carefully matched one to another to make sure they work together as a package. Speed says there are chemicals in many common additives that actively counteract the effects of other additives. So simply dumping a bottle of some additive into your engine during your next oil change can actually leave you worse off than if you had done nothing.
Similarly, choosing a motor oil because it has a higher percentage of a particular additive can also be counterproductive. One of the most popular additives–especially for racers or owners of muscle cars with engines using flat tappet camshafts and lifters–is Zinc, also known as ZDDP, because it creates a protective sacrificial barrier between the camshaft and lifter faces that slowly wears away. More Zinc in the oil doesn’t mean more protection; it means that the additive in the oil will last longer before it is all used up.
There are also different types of Zinc additive packages. Some are designed to work best in diesel engines, some are less harmful to catalytic converters, and some are designed to provide simply to provide maximum valve train protection. Thinking an oil with the highest concentration of Zinc will provide the most protection is a myth because not all Zinc additive packages are created equally. For example, an oil containing 2,000 parts per million of a Zinc package designed to work well with catalytic converters may not provide as much protection for your race car or classic muscle car as a performance oil with 900 parts per million of a Zinc additive package optimized for valve train protection.
The effectiveness of Zinc in your oil is also affected by the quality of the base oil the manufacturer uses. Besides its protective qualities, Zinc is also an anti-oxidant. Manufacturers of lower-quality motor oil use Zinc to mask the deficiencies of their base oil which will begin oxidizing even under normal engine operation. That leaves the Zinc doing a job besides protecting your cam, which means that, just like the previous example, even though the oil may have a higher concentration it won’t protect your engine as well as a performance oil that actually has less Zinc but uses a higher quality base oil that’s not as susceptible to oxidation.
Driven Racing Oil, by the way, uses a brand new fully synthetic base stock known as “mPAO”. Its extreme resistance to both oxidation and heat means Driven’s chemists can use the right additives and in the right amounts that can make a real difference for performance engines.
The “Break-In” Myth
One of the most critical times in any engine’s life is when it is first cranked after assembly. This is the break-in period when all those new parts need to mate together. The common myth of breaking in a new engine is that new parts need to “wear” in.
“The problem with this myth is that people often don’t realize that there is a very real difference between reducing friction and reducing wear,” Speed explains. “While it sounds like the same thing, it’s not. ZDDP is a great example. It is very important for the break in process, especially if you are using a flat tappet camshaft, to use the right type and amount of ZDDP because it reduces wear. But ZDDP doesn’t reduce friction.”
Many people have been told not to break in on synthetic oil because it is too “slippery”. This is because oils are designed to reduce friction, and your engine needs friction to get the ZDDP to activate and help “chemically” mate the parts without wearing the parts out during the break-in period. Low friction motor oils, especially synthetics, are designed to reduce friction which will substantially lengthen the amount of time required to break in an engine.
When an engine is fired for the first and all those parts begin moving together, the engine is essentially finishing up the honing process begun by your engine machinist. As the parts are moving together for the first time, especially the piston rings moving against the cylinder bore, they scrub off tiny pieces of metal that are carried away by the oil. All the things created by your engine during break-in are bad for your engine. This is why you want to complete the break-in process as quickly as possible so that you can change the oil as well as the filter and flush out all the contaminants as soon as you can. Too much friction reduction means it takes longer for the rings to seat and that’s more time the engine is putting contaminants into the oil. A well-designed break-in oil prevents excessive wear while quickly mating the parts. This approach reduces wear and completes the break-in process faster – something a race team can appreciate.
But there’s also a second break-in myth worth covering here. Zinc’s main purpose is to protect and reduce wear. A roller lifter doesn’t experience sliding friction like a flat tappet so it doesn’t need nearly as much Zinc. And because of that there’s a common myth that a good way to break in a new engine with roller lifters is to use the absolute cheapest oil you can find.
While it is true that a cheap motor oil doesn’t provide the same lubricity (or “slickness”) that a higher performance oil will, it also doesn’t have the right chemistry to provide proper protection, either. Believe it or not, there is a difference between lubrication and protection. A good break-in oil is designed to provide just the right amount of lubrication so that the rings will seat quickly while protecting the components from any more wear than necessary.
” We’ve worked really hard to formulate our break in oil so that it provides protection to the engine but also allows it to break in quickly and properly,” Speed says. “It is definitely not the same as our motor oils because it has a very specific purpose. Chemically, it is very different than our other stuff out there.”
The “Racing is Always Better” Myth
It is true that auto racing is a great testing ground for new technologies and components. But that doesn’t mean something created to meet the needs of racers is also the best thing to meet the requirements of a street machine. This definitely includes your motor oil. Even if you have a high-horsepower engine built using a lot of racing components, that doesn’t mean an oil formulated for racing will be the best choice. Keith Jones of Total Seal Piston Rings has a great story concerning this very scenario. He says, “Whenever we are talking to a customer or a potential customer, the first question we always ask is ‘What’s your application?’
“The perfect example of that is the guy that’s building a 632-inch big block that makes 1,200 horsepower running on pump gas,” Jones explains. “And he figures, ‘Hey, it makes 1,200 horsepower, it must be a race engine,’ but he’s driving it around town, it hardly ever gets above part throttle and the oil temp never gets hot enough to boil off any contaminants in the oil. But since he’s making all that power he figures he’s got to run a full race oil, which usually contains very little detergent.
“So with those conditions he will wind up with a lot of contaminants in his oil. A race oil is designed to be changed after every few races, but since he’s driving on the street he’s going thousands of miles between oil changes and that contamination eventually builds up in the crosshatch in the cylinder bores. Next thing you know he’s got an engine that has a lot of cylinder blow-by, it’s got oil control problems and it’s just generally running like a dog.
“So quite often we’ll get a call from that guy complaining because he thinks he got a bad set of rings and now he’s got to tear down his expensive engine and re-hone the cylinders. He’s mad, and you couldn’t really blame him if the rings really were the problem–but there’s really nothing wrong with his motor. I’ll tell that person to go out and get some high-detergent oil, like a diesel oil, run it for a couple weeks and see if his performance improves. And almost every time they will call me back within a couple of days saying, ‘Hey, the engine is perfect again.’
“There was nothing wrong with the engine all along,” Jones says. “The problem was he had the wrong motor oil for the application and it affected cylinder sealing. What he needed was a high-quality street oil like Driven sells that has the proper amount of detergent to keep the contaminants under control while also having the capability to provide proper lubrication for a high-horsepower engine.”
So there you have it. We certainly haven’t hit every lubrication myth out there, but these four hopefully will give you a great start on finding the right oil that is a perfect match for your engine’s needs and will do a great job of helping you maximize both performance and longevity.