I've been doing a lot of reading here lately. I also try to do some research before I speak, but, I certainly don't claim to know everything. I HAD to buy this 08 1500 Big Horn QC 4x2 with 75k on the odometer because some young gal was trying to beat me in an oncomming left turn. She didn't make it and totaled my 2000 Custom Dakota. 'Nuf said about that ... sigh. I have the OEM 20-inch wheels and the 3.92 Posi rear axle. I have been using the 'mid' grade 89 fuel. My MPG has been aroung 17-18. I read with interest about the Sonnax Line Pressure Booster and how some of you have come up with a DIY version. Well ... I purchased a 5-pack of the 2.2K Ohm resistors ($1.07 @ Radio Shack) and simply bent the two leads to form a "U"-shape, snipped the ends of the leads to create a sharp point, and simply pushed the two leads through the insulation into the number 1 and 3 wires of the plug going into the trans. My methood is simply a temporary "fix" to see if there is any real difference. Immediately, I noticed that the trans was a different animal. It shifted sooner and a bit crisper than before. It also now stays in lock-up like it should! I also noticed an increase of 2-3 MPG getting an average of 20 MPG now! ! ! I didn't like the DIY version because it involves cutting the factory wires and I have a 3-year warranty with my truck and I don't want to do domething that cannot be reversed to its factory condition. I will probably order the Sonnax version because I can simply remove the unit and not cause any problems with my dealer. I am an Amsoil dealer and the first oil change is comming due soon. Crankcase and rear end.

I thought I read in my owners manual that I should not use fuels that contain Ethanol?!? Can someone confirm this? Who sells fuel without Ethanol?!?

Thanks to all for the good write-ups and info!

 

Stock axle ratio will be 3.92 not 3.93 JFYI

Your truck can safely run gas with up to 10% ethanol( E10 ). Do not run E85 or any blend % higher than 10%. Do not run fuel blended with methanol.

 

Yeah you'll probably be hardpressed to find many stations without ethanol but this website breaks some down by state.
http://pure-gas.org/