What Is Racing Oil & Should I Be Using It In My High Performance Street Car?

We’ve all seen racing oils sitting on the shelves of our local parts store and wondered if we should put them in our street cars. Looking at the label tells you it has more zinc than regular oil, more anti-foaming agents, and even friction modifiers that add horsepower. Those all sound like positives… so, why isn’t everyone using it?

Let’s take a look at the best-selling racing oil — Valvoline VR1 — and figure out what makes it different from conventional road car oil and if you should be using it in your street or race car.

What Makes Racing Oil Different

The biggest difference with racing oil comes down to the different amounts of the additive packages it’s fortified with, especially zinc. To be more precise, racing oil has higher concentrations of the zinc-containing compound ZDDP or Zinc Dialkyl Dithiophosphate. This is a highly effective anti-wear additive that also happens to be detrimental to your car’s emissions system.

Racing oil, like VR1, also contains smaller amounts of the detergent packages found in conventional oils. (This may sound counterintuitive, but we’ll get more into that a little later.) The last additive we’ll talk about is anti-foaming agent, added to racing oils in greater amounts to fight oil aeration, which reduces effectiveness of the oil in all its capacities.

Most people aren’t tracking their minivans, just like most competitive drivers aren’t running the kids to school in their race cars. (Although I can tell you from experience, kids love being dropped off in the race car.)

Modern road cars operate at low RPM; fuel economy requirements have brought about transmissions with as many as 10 forward gears programmed to keep the engine loping along as slow as possible at any vehicle speed. Racing engines, on the other hand, spend most of their operating hours in a narrow RPM band usually no less than 2,000 RPM below redline. It’s the same when we look at operating temperature and engine load. About the only way a racing engine is treated with more care is service intervals.

The Function Of Zinc In Racing Oil

You will hear enthusiasts going on and on about the importance of zinc in motor oil, and how things “haven’t been the same” since oil manufacturers were forced to use less of it. First, the reason oil manufacturers use smaller amounts of zinc compounds than they did in the past is because it kills catalytic converters.

The very thing that makes ZDDP effective in oil – it forms a thin barrier on top of friction surfaces – is the same thing that makes it bad for your cats. A thin coating of anything on the reactive substrate makes it ineffective. But most race cars either don’t have catalytic converters, or at least don’t have cats with government-mandated, 100,000-mile warranties like your road car does.

There are two different levels of protection that oil provides to friction surfaces.

• The ideal is full film or hydrodynamic lubrication. This is when both bearing surfaces are completely separated by the designed thickness of oil layer and metal-to-metal contact never occurs.
• At the other end of the spectrum is boundary lubrication. This is when the lubrication layer is as thin as possible and contact between the bearing surfaces is possible. In boundary lubrication, the heat and pressure is so high that it activates the ZDDP in the oil and the phosphorus forms a sacrificial layer on the bearing surface. (This is why racing oils like VR1 contain as much as two times the zinc and phosphorus as typical road car oils.)

Keeping Things Clean With Added Detergents

Racing oils contain a lower concentration of detergents than road car oil, but they still have some amount. Detergents, and also dispersants which are commonly lumped together, are compounds known as surfactants, or surface acting agents. These are molecules that have both a hydrophobic end (repels water and attracts oil) and a hydrophilic end (attracts water and repels oil).

Detergents contain metals like calcium or sodium and are alkaline, meaning they will neutralize acids. This is useful for counteracting the organic oils that form when oil is overheated. Dispersants are generally more pH neutral. They are still molecules with opposite heads, but their function is to surround the contaminants and keep them from gathering into large clumps.

Both detergents and dispersants have become critical in modern engines with oil change intervals that might be 10,000 miles. Race engines quite often have service intervals in the 100s of miles, so it’s far less likely that sludge and acids will be an issue. It should also be noted that surfactants decrease the effectiveness of ZDDP, another example of the importance of overall formulation and not just looking at individual additives.

Meet Your Anti-Foaming Agents

You may have seen several unfamiliar words in this article. You may have also seen words you know, but used in ways you are unfamiliar with. Foaming, in terms of motor oil, is exactly what you think it is.

The foaming head on your beer or the crema on your espresso also happens inside your engine. When oil foams, it’s less effective at lubricating, transferring heat, and basically doing all the jobs you expect your oil to do.

The foam is caused by rotating assemblies churning and aerating the oil. It is far more common in racing engines given the higher speeds of the internal components. Contaminants, especially water or coolant will make the problem much worse. But even brand new, clean oil will foam to some extent. Foam is simply gas bubbles trapped in the oil because of surface tension.

Anti-foaming agents, sometimes referred to as foam reducers, break the surface tension lessening the foaming effect. Oils like Valvoline’s VR1 use silicon-based additives which attack the walls of the bubble, weakening them and they eventually pop.

Should I Use Racing Oil In My Car?

The first determining factor of whether or not you should use a racing oil like Valvoline VR1 in your car is if you have catalytic converters. As stated, ZDDP is detrimental to the substrate inside your catalytic converter, but if you have a race car or classic car without cats, you might benefit from using VR1.

The second thing to consider is how often are you changing your oil? If you have a classic or race car, there’s a good chance you’re changing your oil at 3,000 miles or probably less. With a lower concentration of detergents, racing oil won’t be as effective at handling contaminants and acids — but with less time in the car to develop these things, it won’t be as much of an issue.

Does your car need the extra protection of greater concentrations of ZDDP? If you have a flat-tappet or push-rod engine, this is probably for you. Also, if you have an engine with high-rate valve springs, it will also benefit from an oil like VR1 due to the ability to handle higher forces and temperatures.

If you’re even asking these questions, then you likely have a pretty good idea of what’s under your hood and how you use your car. You can contact Valvoline directly through a chat feature on its website, via email, or find your local VR1 dealer and they will be more than happy to discuss the uses and benefits at great length.