Take if from someone who's lifted a couple of vehicles, it will usually always do some noticeable damage to fuel mileage. Then throw on some taller, heavier rubber, and you've knocked down some more mileage. We don't think of trucks having much in the way of aerodynamics, but the further they get from the ground with a lift, funky things occur to air flow and resulting fuel mileage. I only did a 3" lift on a full size '89 Jimmy 4X4 and then installed only slightly taller 31" tires. Just those mods killed at least 2-3 mpg immediately with an unloaded vehicle. You went 3" more in the lift with some decently large tires, so I wouldn't be surprised to see even more fuel economy damage. While I realize there is no fixed formula across the board to measure fuel economy impact because of lifts and tires, it's a pretty universal fact that it's a decently large impact.
Also, you didn't mention your gearing. If you already had somewhat taller gearing and then went to taller tires, the negative impact could be larger. Lifts and big tires can really screw with fuel mileage and performance.
Lots of things can adversely effect fuel mileage: Tire height & witdh more surface contact, aero dynamics, the higher you go more of like a wind hitting against a wall, how well the load is setup, how well the aerodynamics of said truck and load, gearing, "go" pedal adjustment. slower speeds add to fuel economy but too slow can hinder also. you need to find the sweet spot for said load and truck setup.
Thats were you could end up wrong. with intake and exhaust done it can help the engine breathe better therefor making it easier for your engine to tow larger loads. very true the gears will help alot. the chip like with maddogs truck can give you more low end power to move the load faster and easier but also keep your fuel air ratio in at a leaner side to help with mpg.
For instance i traveled 8000 miles for a trip this past summer. i have a 2011 quad cab hemi with 3.55 4x4 stock all around. 4 people 2 adults (300) + (260), 2 children (80) + (40) pounds. thats 680 lbs plus another 220 lbs of luggage. So 900 pounds there @ 75mph, i got 20mpg. On the travel back the said 900 pounds plus a 16' tandem axle 7k trailer with about 3k on said trailer and trailer weighing in at 1k. tongue weight was 2/5 of trailer weight. on trip home with apprx. 5k lbs averaged between 11-16mpg. so a fresh intake filter and oil change maybe to synthetic all around and intake and exhaust with a better programmer could yield a higher mpg. Food for thought.
4.56s may be a bit steep there. Im sure 4.10s if not 3.90s would work just as well and be better for when he isnt towing so he isnt spinning 4K going 65 on the freeway lol
You do understand superchargers take power to make power, and when your towing and under heavy load low rpm situations the blower is going to put more stress and eat more gas than helps with towing? While yes a charger at 2K may be making 2lbs of boost that 2 lbs under heavy load isnt gonna do ya much when the truck is working to spin the charger and the wheels.
Now you put a turbo on it and let the heavy load make the engine work and put out more exhaust gases and spool that turbo down low you are getting in theory "free" horsepower and that may help... ever notice diesels and semis when they start to climb and are in the low RPM range they shoot a ton of soot and black smoke? Turbo is working and making power for them helping them.
Theya re all about effecinecy and run turbos for a reason... plus they sound cooler :smileup:
I understand it well. Gas motors make power differently than diesels. Most of the time the powerband is much higher than off idle.
Gears add mechanical advantage and bring the final drive ratio closer to the powerband. The supercharger does have some parasitic loss by virtue of being belt driven. It was a suggestion, not the only option. I know that there's at least one company (STS) making a turbo kit for the hemi as well. Both will add power when you need it --- and as mentioned the turbo is free power (no belt loss).
As for tuners, intakes and exhausts, of course they add a LITTLE, but the numbers don't add up to much.
^It's really all relative. With my 4.7L, the 93 tune from my superchips adds 67 lb ft at about 3,500 rpm if I remember correctly. That's a (fairly) low rpm for that motor, as it is actually a pretty high revving "cammer" of a v8. That's where I'd want the power added, at a lower rpm. I also sure wouldn't call that "LITTLE". You can definitely add 25-50+ hp with intake, tuner, exhaust. It also depends on vehicle/engine.
best thing to do is have a set of "towing" tires to help your gear ratio, or swap out the rear end. if you have the stock wheels and tires just swap them out beforehand. looks ridiculous but it will help.
^It'd be much simpler than a transmission, and provide great gear range capability. Just a two speed would make your ram a 12 speed instead of a 6 speed. MPG increases, acceleration increases, and towing increases... It can't be that difficult, transmissions are much more involved and trucks have had them for years.
That maybe true. But theres a reason why diesels are the way to go then gas. dont get me wrong gas is cool and fast. but now a days if you want towing constant and decent mpg then you should have gone with a diesel instead of a hemi. hopefully down the road when my two boys are older i can pass the hemi on to them and swap a small cummins 2.8L like was put in a test setup in a titan. though it may be abit expensive to do it all in the end itll pull better, more mpg even lifted, and still look like it came from the factory.
must be the lift and tires like stated above. I tow a 32' travel trailer 7200# with 4 people in cab 2 dogs and average 9-10 mpg if we're going up and down hills it will drop to 7.5-8 mpg but I also keep it around 62mph
I'm running a 6in lift with 35's as well. My mpg took a pretty nasty drop and my new job is a much longer drive both ways. I'm filling up several times a week now =[. And once the snows start to hit, it'll only get worse. I can't even imagine adding a loaded trailer to the situation.