Change Your Oil and Filter: It’s About Time

BROADVIEW, IL – Generally, car owners are aware of the need to change their vehicle’s oil and filter every 3,000 miles or as frequently as the manufacturer suggests; that's been the rule of thumb for years. However, many have forgotten the other half of the rule – change your oil and filter every three months or 3,000 miles! Those words have taken on critical new importance as the spike in gas prices has resulted in motorists driving less than the traditional thousand miles a month.

So, what does time have to do with the need for changing your oil and filter?

“More than you might think it does,” said Ramon Nuñez, Director of Filtration for Bosch, joint venture owner of Purolator Filters, a leading supplier of filters to the automotive aftermarket. Purolator invented the first automotive oil filter in 1923, and the first “spin-on” filter in 1955.

According to Nuñez, time takes its toll on the life of engine oil, and infrequent driving can actually be oil's enemy.

"Combustion gases enter the crankcase and contaminate the engine oil with raw fuel, burned combustion gases, and tiny particulates, all of which compromise the composition of the oil,” he said. “The raw fuel and exhaust gases can interact chemically with the oil, leading to formation of damaging acids. Furthermore, seasonal changes may result in moisture in the air condensing into water in the crankcase. This dilutes the oil and contributes to the formation of rust, corrosion, and sludge.

“Shorter trips don't give the engine a chance to warm up fully and burn off the raw fuel, condensation and other materials that can collect in the oil. Usually, these liquids and vapors are burned away harmlessly in long turnpike-type driving, which is now more the exception than the rule.”

Some motor oils are marketed as 'extended life' lubricants, with suggested oil change intervals of as much as 25,000 miles or more. And though the chemistry of these oils may well perform the job for that long a period of time, grit and other particulates continue to accumulate in increasing and potentially damaging quantities unless they're flushed away during an oil change.

"Our PureOne premium oil filter can capture up to 13 grams of microscopic contaminants, including dirt and metal shavings – the equivalent of 31 standard-size paper clips," said Nuñez. "If the oil and filter are not changed in a timely fashion and the filter becomes clogged, the bypass valve (a safety valve built into quality oil filters) will allow gritty, unfiltered oil into critical areas of the engine where it can cause catastrophic damage.

"In these tough economic times, when people are holding onto their cars longer, it's even more important to protect the engine so it provides the longest and most reliable service possible,” Nuñez. "Changing your oil and filter every three months or 3,000 miles is the cheapest insurance you can buy."

The Car Care Council, a consumer group, warns drivers, that if your driving is ‘severe’ – frequent short trips, driving in stop-and-go traffic, idling for extended periods of time, driving where the air is dusty or dirty, living in a cold region or towing a trailer, it’s better to always stick to the three months or 3,000 miles schedule.