With the heavy-duty demands of diesel pickups when it comes to towing capacity, the expanding horsepower requirements put a lot of pressure on engine wear. And we all know that engine wear is dependent on quality oil providing the necessary lubrication for internal parts.
So the questions are: What is the best oil to insure maximum protection? And how far can you go between oil changes?
Although there are no definitive answers, Cody Crandall, vice president, Oil Analysis Lab Inc., has offered to provide Diesel Tech readers some insight so you can make educated decisions for your own maintenance practices.
Crandall said there are 11 factors that will affect oil life on a new pickup truck: increased emissions equipment, increased operating temperature, decreased oil capacity, oil type (synthetic or conventional), towing, snow plowing, oil level, transmission slippage, turbos, tuning and compression.
“Oil life can vary drastically from truck to truck,” Crandall explained. “The above factors have a huge impact on your truck’s oil life.”
Crandall said that by periodically testing your truck’s engine oil, you can learn if it can be run further or if you should change it. “Through this process you can find out what the optimal drain interval is for your engine and your environment,” he said. “This can save you money through reduced oil changes and maintenance.”
So how do these factors impact oil life? Simply put, they tend to decrease it, or rather, increase its aging process.
“The newer engines tend to run hotter (210 degrees F vs 180 degrees F). This increase in heat tends to oxidize and degrade oil quicker than the older engines running at 180 degrees F,” Crandall explained. “Newer engines have a plethora of emissions equipment that tends to effect oil life negatively. Some emissions systems combined with a more efficient burn can have a positive affect on oil life.”
Crandall said the Duramax is an example of an emissions system that has not negatively impacted oil life. “The engine temperature still runs 210 degrees F like the Powerstroke and Cummins, but the Duramax can experience twice the oil life (15,000 miles vs 7,500 miles).”
Why Test Oil?
So how can an oil test help you save money in the long run?
“Testing your oil assures that you are getting the maximum life out of your
oil and gives you peace of mind that your engine is ready to work when you need it,” Crandall said.
There are five benefits you gain by having an oil test. First, it monitors the oil life by testing for oxidation and nitration. Second, it monitors the engine health by testing wear metal and soot content in the oil. Third, it monitors the injectors for excess fueling. Fourth, it can determine if your air filter is protecting your engine from dirt. And finally, it can detect head gasket failures at an early stage.
Cost and Process
Now that you understand the benefits of having your oil tested, the next two questions are: Is this expensive? And how do you do it?
Crandall said the Oil Analysis Lab charges between $20-$30 per sample. The lab sends instructions (even videos) on how to pull the oil sample. Most will take their samples when they routinely change their oil.
“Some people will pull samples before they travel long distances or know they are going to work the truck hard,” Crandall explained, “just to make sure they have plenty of oil life left.”
Most people purchase their oil sample kits online. The kit includes a bottle, return shipping container, postage and a sample information form to fill out.
“Once we receive the sample, it usually takes around seven days to test it,” he said. “Once the testing is done we send a report to the customer via email.”
Once you’ve submitted a sample and received your results, what’s the next step?
Labs test for wear metals (iron, copper, lead, etc.) so you get an idea of the health of your engine and see potential failures in the early stages, Crandall explained.
“Viscosity tells you how thick or thin a fluid is,” he said. “For engines, it tells if the oil is still meeting the specification in the owners manual (IE: 5W-40) and can also help detect diesel fuel in the oil.”
The oxidation and nitration tests are used to monitor how much oil life you have left. The soot is used to tell the health of your rings. “High soot can be an indicator that your rings are worn out,” he said.
The fuel dilution tests for diesel fuel in the engine oil and tells you if you’re over-fueling your engine or if you have leaky injectors. And then it tests for antifreeze in the oil to see if there could be bad head gaskets or other cooling leaks.
Good question. Each engine has a different “normal” due to usage and driving style. “The information you give the lab on the sample form will help them analyze it and give you the best feedback on if it’s outside the normal range for that engine,” Crandall explained. “Wear metals tend to increase with the miles on the oil and miles on the engine.”
So how can spending a little money on the oil analysis same you money?
“Oil Life can vary drastically from truck to truck,” Crandall explained. “The above factors have a huge impact on your truck’s oil life. Testing your truck’s engine oil will tell you if it can be run further or if you should change it. Through this process you can find out what the optimal drain interval is for your engine and your environment.”
In simple math, if you figure your sump size is 2.5 gallons, you are likely paying around $55 for the oil, $15 for the filter, $50 for labor (or for your time if you do it yourself). So you have $120 per oil change invested in your vehicle … times two or three oil changes per year.
By understanding your oil condition, you may be able to cut the frequency of your changes by 30-50 percent or more. Even factoring in the cost of the oil analysis, your actual cost per mile (factoring all the above expenses) could drop from (depending on vehicle use requirements) 2.8 cents to 1.8 cents per mile (average savings with Cummins or PowerStroke) … or even all the way to 1.1 cents per mile (average savings with Duramax).
Not only does this savings more than pay for the cost of the oil analysis, but the insight it gives you to your vehicle engine health is priceless.
There’s an old adage: You can pay me now or you can pay me later. It just sort of makes sense to pay a little up front so you don’t end up paying a lot at the end.
More information can be obtained at www.oillab.com.