Thought I would post some observations I have been making about the fuel mileage I have been getting with my 2001 Blazer LT 4x4 (4-button TC). Engine, fuel system, and ignition system are all new as are calipers and brakes.

100% Interstate through Northern Indiana rolling terrain at 70MPH with A/C running full blast and cruise on = 16mpg. From several 220 mile round trips to Chicago.

To work 17 miles each way, A/C on, 2/3 county blacktop at 45-50 mph, 1/3 city stop/go (small city of 10000) = 14mpg. From multiple tanks of gas this Summer.

Max observed = 100% Interstate type road for 96 miles through rolling terrain at 50-60mph with A/C and cruise off = 24MPG. Drove to keep vacuum above 14" in Torque Pro app at all times (65mph steady is below 14" and 70MPH is far below 14"). Why 14".... this is the vacuum where the instant mileage reading in Torque Pro starts to take a big dive. To do this I had to allow the vehicle to slow down going up hills while keeping throttle pretty constant and upsetting a lot of speedier people.

I have concluded that my Blazer is an unaerodynamic brick that takes significant power to push through the air at speeds higher than 60mph.

I have concluded that 14MPG is all I'm ever going to get with it in stop/go going to work with the A/C on. It's just too heavy of a vehicle to get good mileage in stop/go traffic.

I have concluded that the fuel mix richens up a lot when vacuum goes under 14". So If I want max fuel mileage I need to drive it with a very light foot under 60MPH with the A/C and cruise off. If I can do that I get outstanding mileage.

I'd be interesed in comparing vacuum readings and throttle position at various speeds with someone else that has Torque Pro or something like it that monitors live data.