Oil and Oil Filter Recommendations
Nov 21, 2002
The Bottom Line This article explains oil, oil filters, and oil change intervals.
Oil is an issue that everyone seems to have "expertise" in. Regardless of who you talk to, they have a strong bias toward or against certain oils, viscosities, oil types, etc. The following is no different, except my recommendation isn't simply based on a conversation with a Pep Boys employee. I've put in a lot of research time and talked with many individuals within the industry. Here are the conclusions I've come up with. First off, regular (read: mineral-based) oils don't offer the heat stability, lubrication properties, longevity, or cleaning ability of synthetics. These oils are fine for regular cars, but if you have a sports car or luxury car, you want to seriously consider synthetics. Synthetic blends are actually a worse alternative then regular oil, because they don't posses the benefits of full synthetic, while retaining the drawbacks of regular oil. You also pay a premium for these ineffective blends. The best option is full synthetic. Full synthetic oil (Mobil1 specifically) is "factory fill" in Chevrolet Corvette, all Porsches, Mercedes-Benz AMG models, Dodge Viper, Ford Mustang Cobra R and all Aston Martin, because of its increased heat stability, longevity, and superior engine cleaning properties. There are many synthetic oil myths that I'm not going to get into here, just know that synthetic oil is superior to regular oil or synthetic blends, in every way. Yes, you will pay a bit more for it, but isn't your car worth it? There is one scenerio where using synthetics isn't advised though. If you have a high milage car (100,000 or more) and it has used standard petroleum oil all its life, don't switch to synthetic oil. Petroleum oil leaves sludge in the engine over the life of your car. If you add synthetics, it will clean out that sludge. The problem is that the sludge is currently sealing the engine and gaskets. If you clean the engine out, it might leak like a sieve. You won't have this problem if you used synthetics for the cars entire life, however. As far as viscosity is concerned, don't outthink the manufacturer recommendation. Currently, almost all new cars are recommended to run 5W-30. If you have an older and/or higher mileage vehicle, you would use 10W-30. 0W-30 is a viscosity that is designed for increased fuel efficiency, but I would stay away from it, because I don't feel it offers proper lubrication. If you do a good deal of racing, you might want to consider 15W-50 or 20W-50. And if you have one of those fancy European cars, you might find a factory recommendation for 10W-40.
Recommendation: If you want the best, two companies come to mind immediately: Amsoil or Mobil1. Amsoil is the absolute best synthetic oil you can buy, bar none. It runs the engine 8-10 degrees cooler the Mobil1 and the engine wear is less. This is the most expensive oil on the market and is somewhat difficult to get your hands on. I use Mobil1 in my car and it's the factory recommendation for Corvettes, BMWs, Porsches, and Vipers. It takes second place to Amsoil, but it's more readily available. Many people happen to love Redline oils, but I would stay away from Redline. Tests have shown Redline oil breaking down after 1000 miles! Royal Purple is no special oil either, especially not for use as extended oil drains (as they advertise). If you don't want to spend almost $5 (or more) per quart, then go with Mobil1 standard oil, its got some of the best additives on the market and its lubrication properties are among the best you can get in standard oil. Your car is probably the 2nd most expensive item you will ever purchase, treat it right and it will last.
Now on to oil filters. If you want to grade oil filters yourself, there are three main criteria: single-pass efficiency, multiple-pass efficiency, and micron rating for particle pass-through. Single-pass efficiency measures a filter's ability to remove contaminants on a single pass through the filter. Unfortunately, single-pass testing doesn't measure a filter's ability to protect your engine under actual driving conditions, where contaminated oil passes through the filter again and again over thousands of miles. That is why multiple-pass efficiency is a better measurement. The best filters are up around 98-99% single pass efficiency and up to 96-98% multiple pass efficiency. The micron rating gives you an idea of what size particles are permitted to pass through the filter. I would make sure the micron ratings is over 50% at 10 microns. Whatever you do, make sure the micron rating on whatever filter you choose is no more then 10-20 microns (10 is optimal). The larger the particles that get through the filter, the more damaging they are to your engine, I can't overstate this enough.
Recommendation: I personally feel Mobil1 makes the best filter, as they have filter surface area comparable to the other top manufacturers (Amsoil and PureOne have slightly larger filter surface area) and they are the only company that uses a coated, fiberglass impregnated filter material (ALL other companies use standard cellulose filter material). You really can't go wrong with either Mobil1, Amsoil, or PureOne. I wouldn't deviate from one of those three. The Bosch and STP filters are pretty good as well, but they don't quite compare to the quality of the above three. As a side note, I would stay away from FRAM, NAPA and Champion filters, they are poorly made/designed. In the filter world, you get what you pay for.
Its become a trend nowadays to hype increased oil change intervals. If you look at Amsoil, Royal Purple, or Redline, you will notice they recommend oil change intervals in upwards of 25000 miles (with their oils of course). The standard oil change interval for the past god knows how many years has been 3000 miles. Many people have said (with some merit) that this is an arbitrary number created to get more money for the oil companies. This number is beginning to change. As synthetic oil technology is increasing and oil additives are becoming more stable, the oil change interval is increasing. In the service manual of most new cars, it recommends an oil/filter change every 7500 miles under normal conditions. That is fine if you drive your car under ideal conditions, but do you? If you look even closer, you will notice that it recommends a 3000 mile oil change interval for severe duty vehicles. What exactly does "severe duty" mean? It means that you are either a fleet car, tow something routinely, drive frequently in stop-and-go traffic, traverse many hilly or mountainous roads with many curves, or drive your car on under 10 mile trips routinely (commuting, etc.). If you drive in stop-and-go traffic or frequently make short trips (as I do, my commute is only 6.1 miles), your engine is experiencing enhanced wear and tear from improper warm-up periods. Since my car qualifies as "severe duty," I change my oil every 3000 miles. Even if it wasn't, I strictly adhere to the 3000 mile oil change interval. My perspective is that I have a massive investment in my car and I can afford to replace my oil/filter every 3000 miles. That is the absolute best thing for my car. I would even prefer using cheap mineral-based oil and changing it every 3000 miles then using an expensive synthetic and changing it every 10000 miles. The longer oil is used, the more contamination, acid and particles it picks up. Regardless of how good the oil is, the shorter you keep it in there, the better it is for your car. This is a good precaution to keep things operating efficiently. I use Mobil1 full synthetic and Mobil1 filter every 3000 miles. If you use Amsoil oil, my recommendation would be to increase the oil interval to 7500 miles, but not the 25000 they recommend. If you use standard petroleum-based oil, I would NEVER extend the oil change interval past 3000 miles. Petroleum oil begins breaking down as soon as you add it to your engine and it picks up acid much more quickly. Additionally, standard oils turn to sludge fairly quickly, never give it an extended change interval if you want your engine to reliably last well past 100,000 miles.
Recommendation: Change both oil and filter every 3000 miles, especially if you use non-synthetic oils. If you use Amsoil, you can extend the oil change interval to 7500 miles.
You can find the above information and additional vehicle maintenance tips/recommendations in the maintenance section of my website: http://www.projectz28.com/ I will be updating it and epinions as time goes on, so check back for updates.