Quote:
Originally Posted by MacCool
Probably not. Modern oils, synthetic or mineral, don't really break down or wax up, but the additives do, especially the viscosity index improvers. Likewise, the detergent additives are only marginally more capable than they were 20 years ago. The real improvements in oil longevity have been catalytic refining and development of the group II base stocks. Extended drain intervals to 6000 miles are based on the subsequent lower need for VI improvers with their shorter life due to shear, but detergents keeping combustion by products in suspension are the current limiting step.
Engine manufacturers and new car warranty providers watch these things closely. They're the ones that set oil performance requirements that the oil manufacturers follow, and they adjust their oil requirements and drain intervals accordingly.
|
Car makers watch it so closely that Nissan recommends 15000km changes for my Z. VW 30000km for my GTi. Both on Castrol 5-30. In Germany. Same motor as the US model. People sit in traffic here etc etc.
Even Porsche in the US recommends recommends 7500mi/12000km changes on the 911 Turbo using Mobil 1. Far exceeding Nissan on a motor putting out much more power and heat.
To each his own but oil is way more durable than you can imagine. For most folks they dont come near its limits.
Fleet managers know it well and are moving entire fleets to longer intervals. Most of this is very old news.
Stop Changing Your Oil! - Edmunds.com - Easy to read no BITOG arguments among oil nerds. The analysis is simple and to the point.