I bought my '90 6.2 K5 in 1994 with 49k on the clock. 700r4, 3.73 gears, and completely stock except for 32" tires. It typically got around 18 MPG and that was mostly city and back road travel (a lot of stop and starting), plus I was young and always drove with my foot to the floor. Rarely did any longer trips on the freeway but I'm sure you could have got 20+ MPG. A good friend of my dad's had a '91 K5 with the 350 TBI and he averaged 13-15 MPG driving the same area and was a lot easier on the gas pedal. I also drove his a few times and to be honest did not notice any huge difference in power over the 6.2.
My K5 now has over 120k on the clock and gets used hard and put away wet on a regular basis. The water pump, glow plugs, and glow plug controller are the only things that have ever been replaced on the engine. They are pretty simple engines with no electronic controls or sensors to go bad.....I guess the EGR did act up and would cause a power and smoke issue but I simply bypassed it.
For the comments about the gas.........a stock 350 TBI should not require premium fuel, and if it does something is wrong or not adjusted correctly. Leaded or unleaded also has nothing to do with the pinging either, nor is related to premium gas in anyway.
My K5 now has over 120k on the clock and gets used hard and put away wet on a regular basis. The water pump, glow plugs, and glow plug controller are the only things that have ever been replaced on the engine. They are pretty simple engines with no electronic controls or sensors to go bad.....I guess the EGR did act up and would cause a power and smoke issue but I simply bypassed it.
For the comments about the gas.........a stock 350 TBI should not require premium fuel, and if it does something is wrong or not adjusted correctly. Leaded or unleaded also has nothing to do with the pinging either, nor is related to premium gas in anyway.
