Gas Mileage?

[GoldOxide_imp]

For Texas heat, 15W40 might make more sense than 10W30. Certainly many lower revving big bore V-twins use it.

Keep in mind with multigrades, a 5W40 and 15W40 are supposed to behave like a "40" when the engine is hot. The "5W" provides improved cold weather start-up protection when needed, especially compared to a "15W". Example: Useful during northern region cold season riding.