Filled up with my 3rd tank and checked my mileage. 13.55 MPG. Only mods are CAI and a 180 thermostat. Being a half ton yukon I was hoping around 18. I don't tow, haven't used the 4wd nor do I get on the throttle. Any suggestions to get the MPG up? Or are more mods necessary. I do use the Standyne performance additive. About 70 highway and 30 town.

May be because of fuel winter blend?

Put a 195 stat back in it and u will get your 18 mpg.

With the 195 stat my truck ran at the 210 mark or slightly higher. That worries me. Should I run the 195 and just get HO water pump?

Did u check your gauge? Mine reads 210, but the motor on the scanner reads 195. The cooler your truck runs the worst milage u will get. If u need a 180 to run a good temp u have more issues to deal with

Did u check your gauge? Mine reads 210, but the motor on the scanner reads 195. The cooler your truck runs the worst milage u will get. If u need a 180 to run a good temp u have more issues to deal with

x2. You may have been covering some issues by using 180 t-stat.
I just realized that diesel needs heat. In the summer 180 t-stat may not be an issue but in the winter? Also, what brand of t-stat did you use?

^ just went off the dash gauge. I guess i'll stop by the auto store and get the 195. With winter moving in I will get the HO water pump later. Radiator is pretty clean. Maybe I am just a little to cautious about the temp thing.

Check your stock gauge, mine was off 20 deg. U may be worried bout nothing

If you need a 180 degree thermostat to stay cool you have other problems.

Make sure you get an Ac-Delco thermostat, the off name ones have been known for inconsistent temperatures.

Thermostat was a duralast from Autozone. I only had the truck about 2 weeks (bought it about the 2nd week of November) when I changed the stat to a 180. Not really sure if the truck really would have ran hot anyways. I think I will be changing it back and like I posted earlier, I will just install a 1997 model water pump. I believe that is the correct year to install that pushes more gallons per hour. I do know that with the storm we just drove this evening, the wipers definitely need replaced.

Don't know if the 94 is different from my 95, but check the space between the radiator and A/C condensor for debris. I had just owned the truck for about a year and had some high temp symptoms. The gap between those two units was nearly 50% clogged. Also check the space between the oil cooler and the A/C condensor. Debris gets sandwiched between both of them, allowing no air flow.

Pull your radiator and clean, clean, clean if you're having cooling issues. Clean between your coolers, A/C, and radiator, and clean your radiator. Some radiator cleaner and a water hose will do wonders on all the crap that can collect in and around there.

The deal is that I am not even sure if my yukon was ever overheating. I am just now on my 3rd tank of gas. I drive it once or twice a week right now. (Both the wife and I are laid off and unemployed). When I put the 180 stat in, it was about 8 or 9 days after I got it. Where the stat goes, the neck was leaking there ever so slightly. I figure if I am going to put a new gasket in to go ahead and install the 180 stat. I do know if that I plan on installing the water pump this spring, then I will be cleaning between the condenser and radiator. Previous owner was a pilot who kept all receipts and the 2nd owner had the yukon for about 3 and half years and only put about 20,000 miles on it before I purchased it. It has been taken really good care of and I just need to make sure that this vehicle runs really good right now while I wait to get a job.

Best of luck on finding a job. That's for sure the most important thing for you right now. Keep us posted on the future work you do on your truck.