Both Shell Care and Staveley Services use plastic bottles to be sent by the USPS. Inside are smaller sample bottles that the oil goes in. Shell's bottles are postage-paid, but either one should be mailed at the counter at the post office. Staveley's form has more questions, while Shell Care wants to know how much fuel was used since the last oil change, which is more work to calculate. Either way, the lab needs all the info to create a meaningful report.
Motor oil is definitely the most common lubricant to be analyzed, but just about anything with lubricant inside could be. Automatic transmissions are prime candidates, being heat-sensitive and expensive to have rebuilt. We certainly wouldn't bother with analyzing the two quarts of dinosaur oil in a Dana 44, but the $100-plus worth of synthetic gear lube in our tow vehicle's rear axle would be a very good candidate for analysis.
Before thinking that oil analysis may be a good thing, but mostly for old stuff, think again. We sampled an '05 Chevy at its first oil change with 1,385 miles on the odometer. At the dealership, they didn't understand why we wanted to use the free oil change coupon so early-we thought it was a bit late. Far from unexpectedly, the oil wasn't exactly clean, and neither was the Shell Care report card. There were quite high levels of iron, aluminum, lead, copper, silicon (dirt), and sodium, among other things. Shell Care recommended a re-sampling in another 1,000 miles and also wrote that, "Analysis indicates typical conditions for break-in." Our point, exactly. Nobody in their right mind would build a fresh motor and not change the oil after a dyno run or initial break-in before installing it in a vehicle. Why then would it be OK to leave the factory fill in a new vehicle for upwards of 7,000 miles with all the new-motor crud in there?
Today's motor oil is superior to that of years past, and any brand-name oil of the correct API grade for your engine should do a very good job. However, while the new oil in itself is generally clean, the containers it comes in can be a problem, says Shell Care's Gene Wagenseller. Although it's rare that something made it into the system, he suggests using a funnel with a strainer, which is definitely simple and cheap enough insurance. Mixing brands isn't usually a problem, but different viscosities could be, he adds. From an analysis standpoint, it could be trickier to figure out what's really going on since different oils have different additive packages, we'd imagine.
Ironically, the first sample is the least informative since there's no history to compare it to. Engines are all different, so it takes a few samples to get an idea of what is normal and have a trend to study for anomalies. Staveley's reports have graphs that show the past five levels of certain contaminants, making it very easy to spot if something unusual is happening.
Helping to avoid costly problems is the main benefit of oil analysis, but to (hopefully) catch a potential problem early is not the only advantage of taking oil samples. It's not uncommon for the lab results to show that the oil could've stayed in service for quite a bit longer than what you may have used for a change interval. Especially with the more expensive synthetic oils, it definitely makes sense to get the most out of them. Of course, oil analysis could also prove that you're running your oil too long, in which case using oil analysis would still save you money in the long run. After all, oil and filters cost much less than the parts they protect.
Whether using oil analysis to extend oil-change intervals, shorten them, or to help prevent the engine from experiencing catastrophic failure, it usually seems to more than pay for itself.
If nothing else, we found it interesting that even our beater Blazer had only five times more aluminum in its very dirty oil than what the nearest local water district lists for its drinking water. Fortunately, perhaps, we don't know how our well water compares.