Why Does a Mustang Use Less Fuel Using Mobil 1 0W-40?
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Question:
Why Does a Mustang Use Less Fuel Using Mobil 1 0W-40?
After reading many tech articles about oil, the API and European ACEA standards, I decided to start using Mobil 1 0W-40 in my Mustang GT instead of Mobil 1 5W-20. I like to rev it, and put a different high octane high performance tune in it. The European ACEA A4/ B4 tougher HS/HT standard gives me more peace of mind. I know ILSAC GF4 stands for fuel economy. But why is it that since I started using 0W-40, my car actually uses remarkably less fuel?
-- Hans Smaling, Potomac, MD
Answer:
Don’t mess with success, but technically this makes no sense. The Mobil 1 5W-20 should provide better fuel economy than the 0W-40 The SAE 20 grade is less viscous under operating temperature than the SAE 40 grade.
