The new HX turbo and 275 injectors look like they have improved my mileage by 2-3 mpg on my work run for the week. That will save me about $700 a year in fuel. Plus the added performance for towing. So it's not all about going fast. Next I'd like to do a Smarty.

I think the bug is nibbling on him..... 

Yes and that is an expensive bug too. It is good to hear the big improvement with your upgrades though! Always makes a guy feel good when you can improve a truck on all levels with some simple upgrades like that.

I think the bug is nibbling on him..... 

No, I think he got bit.

The new HX turbo and 275 injectors look like they have improved my mileage by 2-3 mpg on my work run for the week. That will save me about $700 a year in fuel. Plus the added performance for towing. So it's not all about going fast. Next I'd like to do a Smarty.

So you just replaced the factory turbo w another?  Are those the RV 275's?

So you just replaced the factory turbo w another?  Are those the RV 275's?

Yes his stock turbo was the HY35 we replaced it with an HX35 and put in RV275 injectors.

The Smarty helped my fuel mileage about 1.5mpg almost a full 2 in some instances over stock and I have stock injectors.

Nice! Would I pick up and fuel economy by going with a 4" exhaust and Diamond Eye muffler?

If you want to do the exhaust upgrade I would just do the Diamond Eye exhaust kit that comes with the 4" muffler

Nice! Would I pick up and fuel economy by going with a 4" exhaust and Diamond Eye muffler?

Actually no. Because if you truly running for MPG's you boost should be below 5 PSI if so there is no flowing exhaust really (Back pressure). I'm still running 3" exhaust just straight piped and no issues at all with MPG's.

 

Actually you find slightly warmer intake air temps promote better MPGs more than anything. Between 100-140*F you'll get you better MPG than colder air will.

Whats the difference between an HY to HX?

HX35W turbo is a 12cm2 exhaust housing and a HY35W turbo is a 9cm2 exhaust housing.

Smarty is perfect for a bump in performance and great for MPG gains! I used to get around 18 tops, and with my new 100hp injectors and the smarty set to level 1 i have seen 23 a couple times.

Do I need an air intake temp gauge to monitor?

Doesn't hurt. Live data tool (like ScanGauge II) would do just fine if you want to watch engine data.

What things can be covered with the scan guage? Pretty cheap when you consider the price of gauges and then routing wires to the cab for each gauge is a process.

Basically anything the ECM/PCM has a sensor for.