Your guide to Oil Analysis

Heavily upgraded Ford Explorer ST running E50 and making over 640 AWHP. This vehicle has a long list of performance mods, including a fuel system upgrade, and the oil change interval was at 6,038 miles, with the engine totaling 26,650 miles.  

Key Takeaways:  Fuel dilution was minor at 2.2%, which is normal for a high-performance engine on E50.  

Viscosity was slightly below grade due to the fuel dilution but still within acceptable limits.  

Wear metals (Iron, Aluminum, Copper) were well within normal ranges, indicating the engine is in excellent condition despite the hard use.  

Additives and contamination levels were all normal, with no signs of coolant leaks or dirt entering the engine.   

Overall, AMSOIL Signature Series 5W-30 continues to perform incredibly well even under severe conditions. 

This oil still offers strong protection, and we recommend oil changes every 5,000-6,000 miles for similar setups.  If you’re running similar power or mods, trust AMSOIL to keep your engine protected! 

One of many extended oil analysis from our personal truck. At 27,889 miles AMSOIL Signature Series 10W-30 was still offering the same or better protection than a new oil! AMSOIL Recommends not exceeding 25,000 Miles or 1 year. Severe Duty Intervals of 15,000 Miles or 1 year.

The OG of extended drain intervals for the ISV 5.0 Cummins. Customer went 40,000 miles using AMSOIL Max-Duty 5w-40 and a AMSOIL Oil Bypass Kit. Report indicates he still has plenty of oil life left. Anxious to try AMSOIL Max-Duty 5w-30 Diesel Oil, he changed it and than went 20,000 miles. Sample taken same day he traded it in for a Ram 2500.

This is the first of many for this South Louisiana resident. Sample taken at 11,000 miles using AMSOIL Heavy-Duty 10w30. Lesser oils have shown to drop viscosity as early as 7500 miles. Even with 100+ degree weather and 1,000 miles over OEM recommendations it was still protecting as good as new oil!

5% Fuel Dilution!!!

This is a prime example of why its so important to use a high quality synthetic oil in all modern Direct Injection and Turbocharged engines. But even AMSOIL has its limits. Fuel dilution levels <2.5% will cause oil to dilute and compromise protection. At 5% its at critical levels! Remarkably even though the oil has dropped from a 30 weight to a 20 weight, the high quality additives used by AMSOIL was able to still keep all wear levels at or below the same levels as new oil!

To error on the side of caution though, we upgraded to the Signature Series 5w30 from AMSOIL for the best protection until we can analyze a couple more oil analysis from this engine. Stay tuned for the next Oil Analysis!

This customer falls into the Severe Duty driving conditions. Short daily trips, stop and go traffic, temperatures below freezing, small sump capacity of 4 quarts. Customer really liked the idea of one oil change a year with an average of 10-15,000 miles a year. We knew AMSOIL Signature Series was the perfect choice. All 3 reports look great and show excellent trending patterns!

Justin daily's his 2017 Silverado in the Lonestar State. Justin wanted an oil that would allow him to go two oil change cycles. That's right, when the message pops up on the dash to change the oil Justin resets it and keeps going until it pops up again. While the report shows that it was still good for continued use, Justin is content with this maintenance routine.