ok i got a 04 6.0 i put on a 4in straight pipe s&b intake manifold afe cold air intake coolant filter and sct chip with the street tune was getting 13-15 mpg before what do u guys think i can average now?? also does the sct have a economy tune it comes with?? sct live wire ts

 

13-15 MPG just with more power. Maybe 16 city and 18 HWY...

 

im hoping 18-19

 

18-19 HWY will depend on how you drive.

 

Did trip to Nashville over summer, with 35in. Tall tires and leveling kit, mods described in sig. I averaged 18.45 mpg computing miles traveled and gallons consumed. I did between 72-80 mph but was very calm on throttle, using cruise control most of the time.

 

I run some of the same mods and get the same results for HWY.

 

wow thats good for going 80 and question heat has went out a lil low on coolant ik its not a blown head gasket cuz im not loosing crazy amounts but whats another place i could be loosing coolant and will low coolant result in no heat??

 

i have a 04 6.0 with 4in exhaust, cold air, superchips vivid, and will literally burn' em off~ but not till it warms up. does 15w 40 have anything to do with this?

 

Look at the hose on egr cooler for leak. It drips down back of engine and trans bellhousing. The hose is visible on top of engine by intake manifold down in by block. Look between oil filter housing and intake straight down on passenger side. It leaks just enough to be a pain!

 

TOTALLY depends on driving characteristics, but my truck has same mods. Got 18.4 on a 1500 mile trip. But I drove posted speed limit.
And sure I may hav had a breeze on my bak some of the time. But thts wht I got. Running around? 15?

---AutoMerged DoublePost---

thumbs up to above guy! Solved my coolant leakage tht I "knew" was head gasket! Extra $5k in pocket!!!