Yeah, a tuner can help, depending on the vehicle, and most importantly, the driver. Otherwise, just the usual gas mileage tips... ensure maint. is done, tire pressure, go easy on the throttle, don't add weight, etc. Just keep in mind that it is a full-size truck with a big V8, so don't expect any miracles.
check out PCMforless.com they are getting a little better mpg with there tunes. i had my canyon done by them and it made the worlds diff. they can correct tire size changes, account for intakes and exhaust, cams, boost, altitude...just about anything. i think its around $120-$150 for our trucks.
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