I am going on vacation at the end of the week and was thinking about sending in my PCM for a reflash. I am mainly looking for some MPG gains and heard the power gains are very noticeable. My one question is, what do you guys recommend for shift setting? It is a street truck with 20" Rockstars and 35" Trail Grapplers so I dont wanna go nuts. I was thinking of just doing Setting 2. Another question I had is, will I gain any MPG by swapping for a smaller free flowing muffler? I dont want to do a catback exhaust, maybe just a muffler to get a tad more noise but better flow, is it worth it?? THANKS!!

 

Anyone?

 

I went to Mooresville to get my tune. I had selected option 2 on the shift points. We did road tests until he got it to my satisfaction. One of the things we did on the road test was firm up the shift points. So I suspect that I have a 3 now and I like it. Mine is a 2008 Lux with the stock 265 tires. I do have a Magnaflow catback exhaust and an Airdoc CAI. Driveability much better, small gain in MPG. I would call them an talk to Alvin to see what he can do for you. I am sure there is a fine line between power and MPG. You just have to strike the right balance.

 

I just had mine done last week. I selected #2 for shift firmness. It is very similar to stock, nothing like a shift kit or transpak. Overall I am extremely happy with the improvements. Fuel economy went up 3 mpg so far with the Pcmforless flash, Magnaflow, and Airdoc.

 

So how does it feel? Like I said, I installed 20s with 35s and now the truck is sluggish and dropped some noticeable MPG. I just hate the feeling of either not enough acceleration or too much it just isn't smooth right now if you can understand that. Did you guys go with the regular octane tune? I'm not looking to have a "fast" truck by any means but I would like the MPG and a little easier driveability, hell I have to floor it to pass anyone and its still a dog lol

 

I have already compensated for this...Still only getting 13 at BEST with a 9% fix on my calculation.

 

I am getting 15.5 avg per tank and have 315's with the frt. end leveled. I was getting close to 18 before the tires and level job. I figured I will do the pcm tune and try to get some of that back....?

 

Recently added on magnaflow dual exit exhaust on 3.5 I5 and 315 75r16 Duratracs. At first I didn't think there was too much performance difference because I was driving around at about 50 mph tops. Today, I got on the toll road and started noticing that the H3 was downshifting A LOT more than it ever has. I still plan on getting an airdoc intake and the pcm tune but I'm wondering if those extra additions will help with the constant downshifting. Again, I didn't buy the H3 for mpg's but the constant downshifting is annoying as heck already. Anyone got any experience with a similar setup?

 

When you guys finally get the PCM tune. you will seriously be wonder why the heck you waited so long to do it.

Questions: The smaller muffler thing, wouldn't waste your time, just remove the stock resonator for a straight pipe, or remove the muffler, and run a pipe(s) back from the resonator.

Yes the PCM tune with an intake (like our AirDoc) will help with the down shift, significantly. You will only get it on larger/longer grades and also when it is very windy.

BTW I went with the firmest shifts available, not that big of deal when DD, but excellent when you are really on it.

If you plan on getting an intake, I would suggest you do that first and then get your tune set up for that from the get go. You can always send it back for a re-tune later, but then you have down time or have to do the loaner swap. Either way, get the PCM tune..... do it.