I see that there are comments about different (heavier) weights of oil for the warm seasons. On the past two cars that I have owned, the temp gauge has always stayed in the lower quarter of the range no matter what the season. Does this indicate that the engine is, in fact, maintaining a stable operating temperature regardless of whether it is a hot summer day or winter? More importantly, does this stable temperature negate the need for heavier oils for hot weather? My Honda CRV '04 in stop-go traffic and A/C "on" does not go above the lower quarter of the temp range on the gauge.