i have a 4.7, when i bought the truck 2 years ago it had 18k on it now it has 59k. i do all schedualed work myself all synthetics. i treat her well, i occasionally tow a race car with the truck and house and yard projects make it a well use vehicle. that being said 98% of the time it is just my daily driver. when i got it i was on th fence between the hemi and 4.7, lookin back i prob would have gotten the hemi. the reason i say this is bc i average 12mpg around town and 14-15 highway, as far as i know this is what the hemi gets with a lot more power? is this normal? it has always been this way. i change the oil every 3k with synthetic i am very good about all maint good alignment good tires k&n air filter. any tips on better mpg's or performance. thanks mike

 

When I had my 4.7 RC/SB I had the best gas mileage with a superchips flashpaq on 93 octane tune and 4.56 gears. Remember engine load is more important than rpm.....If you are going up a steep hill and the engine is lugging in O/D force it to drop a gear, youll more than likely get better mileage that way because the engine will be under a lot less load. Oh and from my experience with having both the 4.7 and 5.7.....the hemi has no more power than the 4.7 in normal driving rpms, it excels in higher rpms. My hemi only gets better gas mileage due to mds.

 

ah i see, now when u say a 93 octane tune is that seperate from say a superchip? i was considering getting a superchip 3865. would this have the option for that type of tune through the superchip? wow 4.56's but it makes sense moving all that weight, mine has stock 3.90's in it now i might step up to larger gears u got me thinking.. what milage were u getting with ur tune etc on ur old 4.7. thanks mike

 

No, he's talking about the "Performance Tune" on his SC.

 

yes a s/c 3865 on perf tune and 4.56 will make a good bit of diff add a e-fan and now your talking i have all these and avg 15 mpg city and between 17-20 on hwy depending what speed i drive at....mind this is all from the read out i have never manually calc my mpg's as i drive a truck and dont really care....

 

I would get 440 miles to a tank and that adds out to 16.9mpg. Thats a mix of in town and highway.

 

i get about 15mpg on my hemi with out mds

 

My E-Fan didn't really help mpg interestingly . . . something I'll have to look into. Not thread jacking so don't respond to my sad ending.

But on a side note yeah now that I've been running the sc 91 perf tune and have 4.56 gears I average mid 14 mpg 40city60highway as my DD.

 

sounds like we are in the same boat silent....catch any thing good...

 

thats interesting, i figured that the fan would be my last mod. but now i may just stick to the stocker