Engine oil additives make all sorts of promises about helping your vehicle's motor last longer and increasing your gas mileage. Here's what you need to know.

Some oil additives, for instance, might advise putting in the additive roughly 100 to 300 miles before doing an oil change (and that might be in fine print, so read carefully), which means the ...

Snake oil. Mouse milk. Whiffle dust. Take your pick few products have earned such unflattering sobriquets as aftermarket motor-oil additives. And for Snake oil. Mouse milk. Whiffle dust. Take your ...

Royal Purple’s Synthetic Oil features enhanced additive technology that helps to prevent metal-to-metal contact beyond both GM dexos1 and ILSAC GF-5 specs, while providing better fuel economy ...

Ultimately, it is the additive mix in oil that counts. Additives to control seal swell, shrinkage, and hardening are required, whether it be a synthetic or petroleum product that is being produced.

Synthetic motor oil has been around for longer than you might expect, but most classic cars were designed to run with ...

If you wonder about the purpose of all the chemical additives blended into truck engine oils—especially the new PC-11 formulations coming to market this December—it helps to think about ...

Some mechanics recommend switching to a thicker (higher viscosity) oil — such as 10W-30 full synthetic oil instead of 5W-20 full synthetic — or using oil additives to stop leaks. Thicker oil ...

Synthetic oil, he says, has additives that allow drivers to stretch the miles and time between their oil changes. “Conventional oil lasts about 3,000 miles or three months,” the mechanic says ...

Up until 1972, using synthetic oil in hot rods wasn't common practice. ... (ZDDP), an oil-soluble wear additive with an affinity for metal parts that makes it want to cling, ...

Some additives can help in certain situations, but for most modern cars running synthetic oil that are designed to last up to 15,000 miles, they're about as useful as screen doors on a submarine.