I recently installed the Superchips Microtuner that everyone has been talking about and I can see why there has been so much hype. Made a completely different truck out of my '03 F350 7.3L turbo diesel CC SB 4x4.

What I don't understand is why it is throwing off my "avg mph" that appears on the overhead console. My last tank showed the average at 21.8 mpg by the console, but only 14.2mpg when I calculated it at the tank. Now it is showing 30.0 mpg. What gives??? Did I do something wrong or what???

 

Its unavoidable with any chip or tuner because the mileage calculating computer is not aware of the tune changes. We've covered this many times, especially in the diesel section, that you should not rely on the overhead computer once you install a tune.

 

Ken, thanks for the help. Is there anyway to correct this problem. It would be nice to know sometimes what kind of average a guy is getting.


Thanks,
Brian

 

I know of no one in the past 4 years who has been able to get around it.

 

Newby here to the forum, but a customer of Ford for MANY YEARS. Just traded in my 2003 250 7.3PS for a new F-150 SCREW Lariat. Yea, I know, don't say it! It was a financial thing.

Anyway, I just sold my SuperChips tuner that I had with the 7.3 and want to purchase one for my 5.4. My question is what features of the computer (i.e. milage, distance to empty, etc.) will become unreliable when this engine is tuned? Through a good friend, he has me scared to death that I will screw up the computer on the F-150. Unlike the 7.3, he says there is a lot more to it.

Please educate a new F-150 owner (pictures coming soon). By the way, I am looking at going back with Superchips unless anyone can convince me otherwise.

Danny

 

There are less problems associated with gas tuners than diesels. With diesels you have to monitor exhaust gas temps in the higher settings when towing. This isn't an issue with gas engines, just run premium and you'll be fine. You're friend is needlessly scaring you... the gas tuners essentially do this:

1. Advance the timing for premium fuel. Nothing unusual about this. People have done it for decades with gas engines, including the manufacturers, but turning the distributor (newer vehicles don't have such a distributor).

2. Changing the timing curve. Essentially, not only advance the timing, but being selective about where it is advanced. This could be done with a distributor as well by changing out a part.

3. Changing the air/fuel ratio to take advantage of premium fuel.

4. Remove the torque reduction during the shift. To give a lazy grandma shift for most consumers, Ford programs the computer to reduce power during the shifts. The programmer gets rid of this power reduction. It results in a faster and firmer shift.

5. Slightly increase line pressure during the shift. This firms and speeds up the shift.

6. Slightly modify shift points.

7. Optionally raise the rev and speed limiters.

 

Ken,

Will the distance to empty and average miles per gallon display on the dash still be accurate after tuning? If not, are there any other computer display settings that will not be correct? I am sure this has been beat to death, so sorry if you have had to answer this many times over.

Thanks.

 

No, they will not be accurate after tuning. There shouldn't be any other settings that display incorrectly.