mileage difference
 

So maybe I can get help on this. Im shure Its been posted. I am very happy with my gryphon so far. But as of late it seem like the /87 performance program I got does not seem to be cutting it. Flat spot in accelerator, and seems to go into overdrive alot more.and the gas mileage never went above 13 in the city! ... but maybe its me!. I dont know.. So I tried the regular 87 tow .. and wow what a difference!! ????? got a better responce and I am already up in m.p.g's . I went from 23.4 average m.p.g to 13.4 mpg's... could i be wrong? can the stock tube be better than the custom one I bought..... Moderators?? Bill? Corey? JnJ/? what you think

There are a few things that could be causing this, dirty sensors, dirty filters, dirty throttle body, dirty MAF, or a bad tune. :/
Firstly did the tune ever perform right? as in did you ever see what you are seeing out of the canned tune with the performance tune loaded? If it did then I would bet it is one of the sensors or throttle body that needs to be cleaned, if it never did that good, then I would guess that it is a problem with the tune itself, which Bill can and will fix for free (to the best of my understanding). :cheesy smile:
Your answer to the above question should determine your best course of action, and even if it is just a bad tune, it can't hurt to clean out your engine parts :D. hope this helps.

well she worked great when I first put it in. I did notice a big difference.Having said that I will try cleaning the throttle body, and m.a.f.s. and re check.when it goes in for the 100k im gonna change out the o2 sensor and fuel filter, That will be in about a month. Just seems to be such a change. BUT:shrug: Ill LET YOU KNOW. Thanks.
bobby

That sounds like a good plan :cheesy smile:, Good luck and i hope it fixed your problem :D

Thank you sir!! I will:thumbs up yellow: I promise let you know

So you got 23 mpg city with the tow tune while the performance tune got 13 under the same or similar conditions on paper?

If cleaning everything doesn't help then you might try changing back to stock for a few days then switching back to the performance tune.

well That should actually read 12 mpg. But yea . Yesterday i did a r/t of 75 miles each way about average speed of 65 and got 19mpg. in the stock tow program. But the change from the custom 87 to the stock tow 87 got me almost 2mpg's more!!.So now i show 15m.p.g's average around the city. up from 12-13. and better throttle response. may be it compensates for something?

just a question for ya, what are you using to calculate mileage? because the gryphon for me is usually a few mpg's higher than what I actually get. since it is a calculation derived from the MAF and O2 sensors, it can't be 100% accurate. I usually try and calculate it by hand to see if there are any reasonable changes in mileage, but that's just me. :)

My gas mileage was horrible on the 87 octane tow tune compared to the 93 octane performance tune. I actually save money by running the 93 tune.

I too noticed better acceleration when I switched off my performance tune to my canned 87 tow tune. Interesting....I may need to look into this more.

Ok ! SO may be Bill, can help me/us out on this one? Or any body else?:matt-roloff: I cleaned everything up fresh gas and all and ran the 87 performance tune . Got about 12.5 mpg's in city a nit of a flat spot before and after and not as great throttle .
With the 87 tow I got 13.5 mpg's and a little better all around. Ran a bit hotter but "snappier" .
Could it be a problem with the program? And yes I set it back to stock each time first.

Everyone who is getting "strange" gas mileage results. First, you MUST make sure your Tire Size (TS) and Gear Ratio (GR) settings are correct for the tune you are talking about. If you have not checked the PROGRAMMER DISPLAYED speed or the DASHBOARD ODOMETER READING against some known "standard", you are using figures that are totally meaningless!

IF, you have verified that the Gryphon speed and/or the dashboard odometer reading is correct, then you need to hand calculate a gas mileage figure over 3-4 tank fill ups. I'm sorry, this is the only way to cancel out the effects of winds, climbing/descending terrain, driving environment, differences in filling the tank, etc. One tank full will not do it! I have varied between 17.X and 13.X in different fill ups. My overall average, when not towing, on the highway, is 15.X. Notice those qualifications - in town, towing, it's going to be less.

And, you cannot compare a "meaningless" figure against "stock". The stock tune is a "meaningful" setting. If the tune sees a wrong figure for your TS or GR, then the "tune's" results will be totally out in left field.

And remember, if you have the TS and the GR correct, the dashboard speedo will read about 3% fast. If the dashboard speedo is reading your ACTUAL speed, your odometer is reading about 3% low, which would give you low gas mileage results!

- Jack

I did all that stuff. It wasnt one tank of gas. It was goin on for a while. about the last three months. Its not that I just filled up and went wow the mileage changed! I haven't changed any settings, and my tire pressure is correct and my habits are the same. Thats why i watched it over a period of time. Why I said average m.p.g.'s .It was noticed after using the 87 custom tune for a while. A difference in how it performed. AND THE M.P.G i n 87 mode and then the change to 87 tow.There were no real variables. The only thing I did was change the program.
Thats why I asked the question. Can it be the program?

OK, so I think you are saying you're getting better gas mileage using the tow program?

If you are driving in the city, that's probably the best program to use there. It's a program that helps you get a lot of weight moving from a standstill. And, in pure city driving, I think 13.5 is pretty damned good, considering that you are at low speed or stopped much of the time.

If you asked for a performance tune for city driving, it might very well use more gas. That sounds to me like you wanted something to burn rubber off a stop to get to the next stoplight faster than the other guy.

And, if you asked for a tune for the highway, it's not going to be right for the city.

It's very hard though, to get into your head here. I'm honestly not sure I understand what it is you're looking for.

I was VERY specific when I asked for my tune. I wanted something that would help me pass someone on a two lane road in the 60 mph range. It does that perfectly.

In city driving (New York?) your mileage is going to suck big time no matter what you do. I get about 13.X MPG in Tucson, where the lights are a mile apart and the speed limit (that no one obeys) is 45.

- Jack

AHHHH!! finally some clarity. Yes I am driving around the city in perf 87. And yes I am saying I am getting better mileage in tow, than 87 performance.
See when I ORDERED all I did was tell bill what I did to the truck. But since I wasn't "towing" didn't think I needed to worry. ya know since we all want some performance from the big 8. I was more concerned about mileage .Guess I probally should have just kept asking.
Now don't get me wrong, the 87 perf has woken up the motor just fine,But I wonder if I am gettign better mpg's on 87 tow should I just put it there? and was the 87 perf a miss use of my money. Not a waste.. cause its fun to have.

There's nothing at all wrong with using the tow tune as your daily driving tune. Until I got a "highway" tune, it's the only tune I used.

As far as a "misuse" of money, only you can answer that. I've noticed how people's priorities seem to change with the price of a gallon of gas. Maybe we'll get lucky and it will drop again! :hehe:

- Jack

lol;.:giggle Soooooo now your gonna throw a new one at me ... Highway tune.. ESPLAIN LUCY..LOL

It's simple really, and it's the kind of thing Bill really needs if he is to design "custom" tunes for you.

My truck driving is mostly on the highway, sometimes I pull a trailer and sometimes I don't. If I'm pulling a trailer, we often go up into the mountains (10,000+ feet) on twisty roads where the speed limit is around 25, but you can get away with 35. Otherwise, I'm on the highway going from here to maybe California and driving about 75 mph (65 with a trailer - trailer tires fall apart above 65).

So, I wanted tunes that would help me in these situations. Clearly, in highway driving, I don't have many starts and stops. But, I want to be able to pass someone quickly (on a 2-lane road at highway speeds) and, I'd like to get good fuel economy. You can see I'm not into "Drag Strip Power" here. I've NEVER done a 0-60 or 1/4 mile pull, and don't intend to.

This is what I told him. MOST people he tunes for want something different - lots of low end acceleration. I wanted 60-70mph acceleration, a much different setup.

So, he wrote tunes for me with those concepts in mind. I was able to see improved performance with both of them. It was not mind blowing performance, but enough to justify the tune. (Right after receiving my tow tune, I calculated on a 2,000+ mile trip that the increased economy ALMOST paid for the tune - a $60 tune, since I did the Evo to Gryphon conversion.)

Bottom line, if you want a "custom" tune, you have to explain in detail how you're planning to use the truck. I did this with a letter that I sent in with the programmer when it was converted. I even included pictures of my truck and trailer.

- Jack

see non of that , I dont believe I ever did. When I bought the unit.I really just filled in the boxes on the form. Out down the add ons and that was about it. Never was asked, of for that matter asked myself about customizing the custom performance tune.
I was lookng for a daily driver with better throttle responce, and mileage. With 70% stop and go..
What I do remember was there was a big confusion in getting my tune done. Think it was miss placed for a bit. Then the hex code was wrong caused they tried to rush it out. Bill was away during this time , But when he came back, It was the first to get done.
Well guess then I should have asked more questions about the ''custom tune". May be a box or two , too fill in as to what you want might ave helped this big dummie too.lol.
But oh well, make the best ..Thanks jack!

Well there is a box towards the end of the order form as to what you want out of your tune. I remember I wrote a small paragraph for my first tune back in '09 and a page's worth for my second tune I got a week or two ago.

There was so much there I went :crazy:

:hehe: see cleatus, you thought I was driving you nuts there for a while.. Like I said,, big dummie, But ill just deal for now.. Hey b.t.w Im changing the tires to a 295/65 18. What should the tire size be changes to? I think its asks for a MM SIZE

No, you're not a big dummie. Just caught in the way people normally expect PHP to be a bunch of "mind readers".

As for your tire size, try something in the neighborhood of 2556-2561. That's about a 3% reduction for "squish", the effect of your truck's weight on the tires.

- Jack

yep. you always think they are.. Well I try the tire setting. thanks. They go on next week,.I will try and post some new pics when they do.
Thanks Bobby