Our friends over at Speedway Motors teamed up with Lake Speed, Jr., of Driven Racing Oil, to put together a quick video on how to go about choosing the correct oil for your engine, transmission, and rearend—which may not be as easy as you think.

“A common mistake people make is choosing a brand first,” Speed says. “Then they try and find the fanciest, highest-tech, coolest-sounding product that brand makes, and hope that it works for their application,” he said. Speed points out that while brand loyalty and confidence is a good thing, it shouldn’t be the starting point of picking the right oil.

Instead, the first, and most important consideration for your oil choice, is the application in which it’s going to be asked to perform. That should dictate everything that follows. “When you choose an oil, be it an engine oil, transmission oil, or gear lube, it’s helpful to start by focusing on application,” says Speed.

The process for choosing the right oil should be driven by an honest assessment of your needs and the demands you will actually place on the oil. Remember, you don’t lie to your doctor or engine builder.

Just because your muscle car has the same engine as the guy down the street who has a drag car, doesn’t mean they should be running the same oil. “The oil that is needed in a sprint car running on methanol is very different than the oil in your hot rod, even though they might both be similar V8s,” explains Speed. “The type of fuel used, along with the conditions the engine has to perform under, put different demands on the oil.”

Once you have honestly assessed your application, then it’s time to look at the oil’s chemical makeup. “The application dictates the chemistry,” says Speed. “If you have an old-school Powerglide or Turbo 400, a Type-F transmission fluid – which is a high-grip fluid  – is a much better choice than a modern synthetic Dexron VI transmission fluid which is slippery.”

The same can be said of engine oil. You wouldn’t want to run break-in oil every day in your weekend cruiser, nor would you want to run a racing oil on the street, because of the difference in chemistry between the two formulations.

“Let the application dictate the appropriate chemistry, and then choose a brand you trust that meets those needs,” concludes Speed.