Project Farm

How Bad Are Cheap Motor Oils (Diesel Engine Oil)? $14 vs $58

Todd's Picks

Best Overall Performance

Amsoil Signature Series

Purchased for: $58

Made In: USA

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Amsoil Signature Series offers the best anti-wear protection and durability, making it the top performer in our tests.

Best Flow Speed

Hot Shot’s Blue Diamond

Purchased for: $55

Made In: USA

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Hot Shot’s Blue Diamond excels in flow speed during cold starts, ensuring optimal engine protection in extreme temperatures.

Best Anti-Wear Additives

Schaeffer’s

Purchased for: $42

Made In: USA

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Schaeffer’s provides a robust anti-wear additive package, ensuring long engine life and performance.

Tools Tested

Mobil Delvac

Purchased for: $14

Made In: USA

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Rotella T6

Purchased for: $23

Made In: USA

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Royal Purple

Purchased for: $30

Made In: USA

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Schaeffer’s

Purchased for: $42

Made In: USA

Buy on Amazon
Hot Shot’s Blue Diamond

Purchased for: $55

Made In: USA

Buy on Amazon
Amsoil Signature Series

Purchased for: $58

Made In: USA

Search on Amazon

Showing 6 of 6 products.

Price per Gallon

Lower evaporation loss indicates better resistance to thermal breakdown and oil consumption.

Smaller wear scar sizes indicate better anti-wear properties and longer engine life.

Faster flow times in cold conditions ensure quicker lubrication during engine startup.

Higher additive content provides better protection against engine wear and prolongs engine life.