Got a chance to do a tune comparison. And got some surprising results.
Drove from Huntsville, AL to Baton Rouge, LA and back for Thanksgiving.

Base info:
Truck specifics in my sig.
No trailer, only the truck.
All tires pressures set to 60 psi cold.
AIT stayed in the 30-50 deg range.
Coolant temp 190-194 deg.
Engine load 15-65% depending on the overpasses I encountered.
Mobil1 5W30.
Cruise control set at 75 mph (by my GPS, speedo said 77) for a real world test, never touched the brake or accelerator unless needed due to traffic. I would say 95+% of my drive was just allowing the cruise control to do it's thing, good or bad.
Filled up each time at an off ramp Chevron station, so no in town driving what so ever was involved.

5-Star 93 Octane Perf tune w/93 Oct
383.90 miles driven
28.02 Gallons used
13.70 mpg

5-Star 91 Octane EconoPerf w/89-93 Oct blend (sorry, we don't have 91 here)
220.00 Miles driven
17.17 Gallons used
12.80 mpg

Surprising to me that the Perf tune got 7% better mileage than the EconoPerf tune did. But that might be due to higher ignition timing in the 93 Perf tune.

The difference in price between the two octane fuels was $.14 which is roughly 5% more in cost between Plus and Super grade. So by my math (which isn't always the greatest), the better mileage off-sets the higher cost of premium fuel by a positive 2%. This confirms what I thought would happen when the engine is allowed to work with higher octane fuels and tuning that takes advantage of it. I wonder if that benefit would be even higher going from 87 to 93 Octane?

So are you really saving any money by using the cheapest grade fuel? From what I got here, it could be costing you more. But keep in mind that you need a tuner to get the benefits. Seems to be worth it to me.

Any thoughts and comment are welcome.

 

So those numbers are all highway? The 1-2mpg increase usually only pertains to 91-93 and all highway miles. My trouble is the majority of my mileage is not highway.

 

Yes, all HWY miles

 

depends on the tune...

i tried the same thing using higher grade gas for several tanks (combined city/hiway) and found the truck worked better, but mileage was pretty much the same...

but im certain its because the stock tune is crap...i bet with a 5Star, my results would be just like yours...

 

I noticed a .5 to 1 mpg better on 89 rather than 87 on the stock tune. I think some of it has to do with the gas you even start out with. This CA gas is junk. 10% ethanol at all times.

 

It's 10% ethanol here too.

 

I always get 14 mpg on hwy with stock configuration ( though I cruise about 60-65 mph ) .

Once I got curious and made a search at US Patent Dept. to see if a particular claim has any technical merit . This person was supposedly worked for Ford Motor Co. as a designer . He is currently marketing all kinds of performance enhencers and MPG savers for the unsuspecting and the naives .These are sopposedly increasing performance for both diesel and gas engines .
I found no record of any patent on any of these products he is marketing , it also appeared that he failed, as a designer , to come up with any patentable idea during his decades of work at Ford Motor Co. .

In our corporate world , there are army of engineers whose job is to evaluate emerging technologies and products . If they run into a product ( claims like mpg saving or HP increasing designs ) , they buy the entire company before the compitition does . This will give them tremendous adventage against competition .

So , buyer beware , if there is no patent , it does not work . Do your homework before purchase .

Ken

 

Well that would be true for almost all the gizmos and whatchamajigs but there are lots of things that still can help... i mean ford doesnt want the motor to be maxed out for power or get the most mpg its capable of, they have limitations and other things to consider. Look back to the 351M/400 motors for example. To help pass newer emissions they retarded the cam by 4* and detuned the carb. and that chocked the crap out of the motor and hurt the power and economy. Was that a brilliant idea by cutting edge engineering department LOL! Just sayin...

For the record my rig is averaging 13.5 currently over the last 6182 miles thats combined everything. But I havent pulled much in the way of weight yet.

 

Ah, now that the winter blend is here, 9.65 mpg's mostly city. Down from 10-10.5mpg's.

 

Wow, very impressed with your detail in fuel mileage calibrating, just got the 5 star tuner myself and have only put 4 miles on it since, but from what I can tell, the performance tune rocks, so why bother with the economy tune? Keep it in performance tune and just replace pads and rotors more often.

 

If the "blend" that you made up was a bit on the low side for octane (less than true 91),then the knock sensor could have been staying active a bit more than normal and retarding timing, which could have caused a bit of detriment to the fuel efficiency numbers that you saw with a tankful of 93 on the other tune.
JL

 

It was close to a 50/50 mix with slightly more 93 Octane.

 

Fuel blending is not linear and a 50/50 mix does not equal 91.
JL

 

50% 89 and 50% 93 should have me at 91 octane.

 

Fuel blending is NOT linear,and 50% 89 and 50% 93 DOES NOT mean that you have 91 octane in the tank. It is not that simple.
JL