Ok, the test is complete for the 87 Performance tune setting. My last tank was back down to 14.95 mpg probably due to a little more city driving than usual. I am returning the tune back to stock but will "tune the transmission" with the settings available.

I will continue to report the results here so interested parties can see my real world results (or lack thereof). Wish DS would tweak the MPG Booster tune for some decent mpg improvements.........

 

First tank after returning back to the stock tune saw my mpg drop back to 13.76. In defense, there was a higher percentage of city driving than usual (about 50%more and I loaned the truck to a relative).

I have decided to try a new experiment.......93 Performance tune and E85. I expect to get a Check Engine Light and maybe some drivability issues but I am willing to try it and see. Just filled up (25.32 gals) with E85 at Valero for $2.99/gal vs. $3.39/gal for 87 octane (which has 10% ethanol anyway). Saving $10 at the pump was nice but we'll see how well it performs....or does not perform.

Onward thru the fog...BOHICA!

 

You just put 25 gallons of E85 in your 5.7 hemi powered ram ?

 

Does E85 even come in 93 octane? If feel like that combo is dangerous for the engine. Only the 4.7 Flex fuel engine is made to run safely on that.

 

e85 is a bad idea in a hemi

Tuning for 93 and running E85 is worse

At lower altitudes (seeing as how you live in texas) you really need to run higher octane fuel in the hemi, it calls for 89.

 

Yeah, rolling the dice on this one. Especially with 90K miles. So far it runs nice but did throw codes P0171- System too lean Bank 1, and P0174- System too lean Bank 2....but I expected that. Probably should pull a plug and see what that shows. We'll see.......

 

It takes more ethanol than gasoline to make the same amount of power and also ethanol will decrease your mileage. Not a very good experiment

 

The results from the 1st tank are lower than hoped but probably as expected. My mileage was 12.71 mpg vs. 13.76 mpg for the previous tank of 87 octane on stock tuning. After doing all the math, I saved about $3.35 for that tank over 87 octane gasoline (already 10% ethanol). I'm going to do at least one more tank, pull a plug and check to see how lean things are running, and then move on to the next test.

By the way, E85 is rated at 100 to 105 octane according to HotRod.com (http://www.hotrod.com/techarticles/h...l/viewall.html) so I am not worried about pinging with it on the 93 Performance Tune.

The only drivability difference I noticed is that it cranks for about a second longer on a cool morning after sitting overnight. Other than that, it runs great!

 

Ethanol also will rot your fuel system and cause phase separation in the fuel. Meaning, after a while, you'll be sucking in straight alcohol/water.

 

I considered that and decided to go ahead and test it anyway. My research on the internet led me to believe that most, if not all, the newer fuel systems are already compatible with ethanol. If I'm wrong..........I will certainly post it here so that others don't decide to follow. If I'm right, then we (I) have confirmed something previously speculated about.

After this second tank of E85 is finished, I plan to go back to 87 octane gasoline with the 87 Performance tune because that has given me the best mpg so far. After all, this test is all about economy with no noticeable loss in driveablity.