Issue link: https://read.dmtmag.com/i/112433
Maintenance matters it���s rare these days, the best place to start the description is with a single weight oil. A popular choice many years ago was straight 30-weight motor oil. That rating was a simple measure of how cold the oil could get and still pour. The problem is there���s a trade-off. A lighter weight (thinner) oil that remains pourable at a lower temperature does not maintain its protective ability as temperatures increase. A heavier (thicker) oil that protects better at higher temperatures does not remain as pourable at lower temperatures. The answer to this problem was the development of multi-grade motor oils several decades ago. A rating such as 15W-40 meant that the oil had the cold-weather pourability of a 15-weight oil, and the high temperature protective ability of a 40-weight oil. Early 5W- 20 synthetic oil debuted at a time when typical multi-grades were rated 15W-30 or 15W-40, so its thinner consistency was able to provide reduced engine drag and thereby increased fuel economy, while still maintaining hightemperature protection. The extra refinement of synthetic oil enables the lower viscosity to perform better at higher temperatures because there are fewer impurities that the heat will turn into sludge, and the extra refinement also makes the oil more resistant to chemical breakdown or evaporation. While conventional oils need to contain more viscosity modification additives, and thereby less lubricant to maintain the multigrade performance, the synthetic oils reduce the need for these additives, improving overall performance. OO / Owner���operator/ March 2013 / / 64 OO 0313_text.indd 64 2/6/13 4:29 PM