Who car's are fully synthetic?

[Lazerdot]

According to the AMSOIL tech I talked to, about 86% of the driving in the USA falls into the "severe condition" definition. Not sure if that includes long haul Trucking or not. Most oil brands sell the product based on the maximum life available. Amsoil does the same, therefore you'll find 25000-35000 miles/1year miles advertised. Other oils advertise up to 15,000 miles/1 year. But, severe conditions require a greatly reduced oil change interval, in many cases right back to OEM intervals. Amsoil's interval decreases to 15,000 and 17,500miles respectively under severe conditions. I sell AMSOIL with the severe conditions in mind. Filtration needs to be kept up with anytime an extended drain interval is used. Many filters can be used up to the OEM oil change interval. AMSOIL has EAO filters that last up 25,000 miles in most applications, not the Yaris. The MANN filter that can be used in my Yaris is good for 7500 miles when using AMSOIL. AMSOIL no longer recommends it's EAO09 filter for the Yaris. Amsoil has restricted the EAO filter life to OEM on other Toyotas due to some unusual contaiminate amounts in these engines. No matter which brand, always change your filter whenever you change your oil.

So, if your going to use the 35,000 mile SSO AMSOIL, make sure your plan on filter changes at OEM intervals ( or 7500 with the MANN) regardles if you change your oil at that time. Determine what type of driving you do and whether the max interval really fits your driving conditions. Do an oil analysis as you near the 15000/17500 mile point if you plan on going for the max drain interval.

Check out the Auto-Light Truck lookup on Trulube.com for all your fluid and lubrication needs.

Maybe a bit of over info, but rather you have it.