2006Tahoe2WD
Full Access Member
My 2006 Tahoe 5.3L, not flex has 123k miles. I got it with 100k miles and by the look of the plugs at 123k miles they were not changed. Prior to the change I noticed some hesitation in various conditions so I decided to change the plugs and wires. Before I made the change I took a 1000 mile trip and made a note of the average mileage per the display, it was 19.1 mpg. After I changed the plugs and wires I made a 600 mile trip and noted the displayed average mileage - it was 20.2 mpg. I wouldn't say the two trips were exactly the same - both involved some hills, both had lots of freeway driving at 60-70 mph. I feel the engine runs smoother at all loads and speeds but this is subjective. The plugs I installed were 41-110 and I used ACDelco factory wires. The hardest part was getting the old boots to unclip off the plugs. I was able to get my torque wrench in there and torqued the new plugs to 11 ft-lbs with copper anti-seize added to the threads.
