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Discussion Starter · #1 ·
I know this is a much talked about topic but I'm just trying to find an answer. About a year ago my e99 f350 was getting 17mpg average on the interstate doing a constant 70mph. The truck died one day and turns out it needed a new pcm so the dealer put one in. Anyway, since that day my mpg have never gone above 14mpg town or hwy. I'm not mad, I just know I was getting 17 and want to figure out why the mileage dropped. I've put a 6637 intake on, ebp tube is cleaned and sensor is new, 4in Turbo back exhaust. 235/85/16 tires. New intercooler boots all around, bellowed up pipes. My brakes aren't stuck I just check 5 days ago. I thought it might be a faulty pcm so I put a chip in from dp tuner with custom tunes. That didn't fix it. I've scanned it with an AE scanner and everything checks out good. I have 3.73 gears at the back. It's 4x4. No my hubs aren't locked in. Oil is good and fuel fter is clean. Any ideas? I've tried any mpg mod I can think of and nothing has worked. I just don't believe I can get 17mpg then instantly drop to 14 and never get more.
 

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Is this hand calculated or the lie-o-meter?
 

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Discussion Starter · #3 ·
Always hand calculated. I'd love if my lie o meter was right because I'd currently be getting 28mpg.
 

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Discussion Starter · #5 ·
They did also replace the cps (although it wasn't bad) which in the long run I found out was the black original cps. From what I understand some say you get better mpg with the black one, but I don't see how my miles would drop 3mpg from that sensor. I've tried the grey cps and dark blue cps. Both only get me 14mpg.
 

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It is completely because of the catch code in the original computer that was in the truck.
Now the new computer, I guarantee has a later date / higher number catch code AKA updated profile, so it probably runs and shifts better, but gets worse fuel economy..

 

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Discussion Starter · #7 ·
Maybe but isn't that the purpose of a chip? It overrides the computer and the chip is technically your computer? And if the catch code is the problem. How do I fix it?
 

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When the stealer ship installed the new PCM, they loaded the newest strategy for your catch code computer, which means less emissions and poorer fuel economy and different shift points and converter lockup.

The only way to correct this is with a good chip. Not a generic tuner.
Not a DP-Tuner either.
(Junk)
Get a PHP chip with Gearhead tunes. You will prob get 18 mpg.


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Dp tunes have become better in the last few years. I'll give them that.

Aren't 235/85's taller than stock tire?

Also in some cases swapping from the original to the grey cps will cause a mpg drop just like you are experiencing.
 

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The only way to correct this is with a good chip. Not a generic tuner.
Not a DP-Tuner either.
(Junk)
Get a PHP chip with Gearhead tunes. You will prob get 18 mpg.


Sent from my iPhone using Tapatalk
I have a DP Tuner and I've had it for over a 100,000 miles on my truck. It is, without a doubt, the best thing I've ever done to my truck. I have a lifetime average of 18.1 MPG hand calculated with their tunes. That's combined daily driving and towing. Their product, in my opinion as well as the overwhelming majority of individuals on this forum who have tuned trucks, is that DP-Tuner is the top of the game in this field. They've been around longer than any of the others, have much better customer service than most if not all of the others, and stand behind their products. I've recommended and helped install their tuner on more friends than I can count and every single owner is ecstatic with the result. The only complaint I've ever heard is about whether the grin you get driving a DP-Tuned truck might become permanent.

Now - I would never be so brazen as to call PHP, TW, Gearhead, or any other of the johnny come lately companies "junk", but it doesn't take a lot of research on the forum to find threadS about buyers not being able to get someone to come to the phone, answer e-mails, truck won't start, burned up my PCM, etc. That just doesn't happen with DP-Tuner. A couple of their staff and one of the owners even participate on our forum helping answer questions.

Sorry if this was long - just can't say enough good things about that company.
 
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Actually php has been around the longest.

I don't mind dp's new tunes. My friend is running them with 160/30's and they are much improved over their tunes from a few years ago.

The cost for their tunes is pretty steep though, compared to other companies.
 

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Not bashing DP , but it did destroy my PCM And the tunes are nowhere as good as Gearhead.
I have about 15 years of powerstroke tuner/chip/tunes experience.
Jodys tunes are not even close to the best anymore. They used to be.


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Not bashing DP , but it did destroy my PCM And the tunes are nowhere as good as Gearhead.
I have about 15 years of powerstroke tuner/chip/tunes experience.
Jodys tunes are not even close to the best anymore. They used to be.
You are bashing them - you called them junk and not even close to the best anymore. That's an opinion, which you are entitled to. Just don't state it as fact. You have nothing to back it up with other than your own personal experience. I'd be interested in the results of an investigation into how your PCM was destroyed. Was it an installation error or are you alleging the program melted your circuits? My opinion, based on my own truck and about 24 others I've helped install, is that their tunes are fantastic. Their customer service is phenomenal.

My request to you - you've managed 158 posts in 10 years of membership on the forum. Use some of your next posts to help people with some constructive advice addressing real world mechanical issues and less of them like the last one.
 

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Well stated. I for one have been helped many times on this site and hope I will be able to pass that on to someone. That being said, if the products we purchase don't evolve we move on to ones that do. Factual info is gold, opinions without are just limited
 

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P

I recently changed engine oil to synthetic and picked up 1.5 mpg city and 3 hwy. This data is by computer but something changed as a result of oil. Will hand calc it next fill up. Was getting ready to switch over to synthetic trans fluid for towing and wondering if that will contribute to better mpg. Always had 14-15 in city and no better than 17 hwy with 285 tires. Getting ready for gauges this month and maybe tunes later on.
 

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As a new DP Tuner Infinity owner, I must say "Amen" to RT's comments.

Wonderful product with great customer service!
Mike
 

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Lucky. My bone stock 7.3L drw has never gotten better than 14 mpg, hand calculated. Towing gets around 7 mpg...
 

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I got 14 once (with a 30mph tailwind) avg 12 and 7 LOL
 
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