SnowDrift
Ultra Conservative. ULTRA!
Biggest problem with the aluminum is they didn't make them big enough. In the old copper you could get 4 and 5 rows. Only 2 in aluminum.
The aluminum 2 row is a very wide row. I wondered about the same thing years back. I occasionally gross +31,000 lbs in the summer with the A/C on and haven't had much need yet to turn the A/C off to keep it cool unless in stop and go traffic in a town. I believe the aluminum factory setup is sufficient.