| Fuel economy suffers in the winter mostly because of increasingly oxygenated gasoline. Engines run at largely the same temperature regardless of outside temperature, because of the warm-up enrichment that occurs at startup. It is true that an engine in the cold enrichment state will consume more fuel than otherwise, but the VG30DETT warms up significantly faster (and has a consummately shorter cold enrichment period) than your average passenger car motor. It's also true that cold enrichment happens every time you start the motor cold, including the summer.
Your powers are useless! I'm wearing my tinfoil underwear! |