OIL AND OIL-CHANGE INTERVAL, AND OIL FILTER BRAND RECOMMENDATIONS
Q: What is the best motor oil to use in my car and how often should I change it? What is the best brand of oil filter?
A: These questions have more answers and opinions than there are grains of sand on a beach. Read opinions at the following site and become one of the opinionated on these subjects:
http://theoildrop.server101.com/cgi/ultimatebb.cgi
As a general rule, if you want longer oil-change intervals and don't mind paying more for your oil, use an oil with a synthetic base stock such as Mobil 1, Castrol Syntec, etc. Use the oil viscosity that is recommended in your owner's manual.
OIL ANALYSIS AND OIL CHANGE INTERVAL
To determine the optimum oil change frequency for your vehicle requires that you perform several oil analysis during one oil change interval. For example, if your vehicle has 15,000 miles on it and the manufacturer recommends 7500 mile oil changes for normal service and 5000 miles for severe, perform an analysis at 18,750 miles, 20,000 miles, and 22,500 miles (if the first or second test shows a need for an oil change then stop there). Do not exceed the manufacturer's normal service interval even if the analysis shows no need for an oil change at 7500 miles. The oil change industry desperately desires that you NOT perform such an analysis. The almost certain result for most drivers will be that even at 7500 miles the oil will still be fine.
Even after your vehicle is out of warranty it is a good idea to continue to follow the manufacturer's schedule for maintenance. There are frequently special campaigns (not recalls) to fix latent defects after the warranty has expired. Lately we've seen these on some Toyota V6 engines and some Saturn engines. You want the manufacturer to have no excuse to deny coverage. Also you can sometimes get a manufacturer to share the cost of an expensive repair when something fails after the warranty has expired, but this is at their pleasure and it is best to have solid proof that you have followed the maintenance schedules.
Big oil users like bus companies and truck fleets use oil analysis to extend the life of their engines without unnecessary oil changes. The reasons are clear. These big engines can use 3-4 gallons of oil and unnecessary changes are expensive in both time and materials. In some cases they change the filters and put in additives to replace the acid neutralizers and anti-wear agents. A good analogy is swimming pool maintenance. You clean the filters, you remove the debris, you add stabilizers and disinfectants, but you rarely empty the whole pool and refill it.
Two places to get your oil analyzed are:
Lubricon Lubricant Consultants, Inc 350 E. Churchman Ave. Beech Grove, IN 46107 (317) 783-2968
Cleveland Technical Center 18419 Euclid Avenue Cleveland, OH 44112-1016 (800) 726-5400
API CERTIFICATION, PHOSPHOROUS & ZDDP
Never use a non-API certified synthetic oil (there are many of these on the market). The problem with the non-API certified synthetics is that they contain too much phosphorus (in the form of the additive ZDDP (Zinc Dialkyl Dithiophosphates)). The API has limited the amount of phosphorus because phosphorus shortens the life of the catalytic converter. These oils are fine for snowmobiles, motorcycles, and older cars that don't have a catalytic converter, and the extra ZDDP does provide additional wear protection.
Unfortunately, the marketers of some the non-certified oils do not explicitly and honestly state the reason for the lack of API certification. You can check the status of API certification on the API web site. Be certain to go not just by the manufacturer name but by the actual product as well. This is because a manufacturer often have both certified and non-certified products. Suffice it to say that Mobil 1, Royal Purple, Castrol, & Havoline all make synthetic oils that are API certified and that can be purchased at auto parts stores and other retail outlets. AMSOIL has one product line, XL-7500 that is API certified, but it's other lines contain too much ZDDP to be certified and should not be used in vehicles with catalytic converters.
MOTOR OIL MYTHS AND FACTS
http://www.nordicgroup.us/oil.htm
OIL CHANGE PROCEDURE AND RECOMMENDATIONS
http://www.automotiveforums.com/vbul...41#post3157041
OIL FILTER STUDIES
Q: What oil filters are the best?
A: Here are studies performed on various brands of filters. Make your own judgement:
http://www.frankhunt.com/FRANK/corve...lterstudy.html
http://www.frankhunt.com/FRANK/corve...ilfilters.html
http://www.scuderiaciriani.com/rx7/oil_filter_study/
http://www.oilfilterstudy.com/
OIL ADDITIVES
Q: What about the various oil additives?
A: Here's a discussion on the subject:
http://www.offroaders.com/tech/snake-oil.htm
In general, lubricating oil contain additive packages that have been certified to provide a minimum level of protection as specified by the specification they meet (SF or whatever). Adding an additive to the oil is something you should do sparingly.
For a discussion of additive packages, see:
http://www.dirtroadmagazine.com/oil.htm