PCM TUNING

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Oct 23, 2007 | 10:22 AM

#21

Gunner_45

Senior Member

Joined: Dec 2006

Posts: 2,075

From: North Central Texas

RE: PCM TUNING

Quote:

ORIGINAL: HUMMER DRIVER

The catback (Magnaflow) didn't seem to hurt my mileage a bit. I was getting right at 20MPG highway until I put those big honkin Super Swampers on my ride.

I have a K&N intake, PCM update and dual exhaust. Like I said, mileage with stock wheels is great provided you obey the speed limit. Since going to the large tires I can tell you my mileage has suffered a great deal.. I don't plan to run the Swampers all the time. I will put my stockers on and click some hiway miles with them too.

On my old '06, the tires and the leveling were good for a 3 to 4 mpg hit ! ! !

The PCM tune on the totally stock '06 did seem to help, but I traded it in on the '07 before
I realized the full benefit of the tune.........

On the '07, with just the tires.....I'm @ 14 to 15 mpg on a good tank staying @ 65 mph mostly highway...

It just rolled over 2000 miles and I've only checked a few tanks. It's been in the shop more than it's been on the road,
so I really haven't had more than 2 consecutive tanks to compare...