0W40 vs 5W40: Which Oil Grade Boosts Performance & Fuel Economy?
0W40 and 5W40 are multigrade motor oils; the number before the “W” tells you how fluid the oil stays at –35 °C and –30 °C respectively, while the “40” means they stay thick enough at 100 °C to protect the engine. Drivers often stare at the shelf wondering if the “thinner” 0W40 will give them…