my dad has a 2005 crew cab 6.0 4wd 1500hd and he was wanting to know what cai would give him the best fuel mileage increase. he does not care about performance just wants better gas mileage...... any other fuel saving products that you can think of will help too...

Thanks Robert

 

Tell him not to waste his money.....my .02

 

Ram air helps lean the engine a little more and forces air in at highway speeds so best bet for that is Volant. Also free flowing exhaust and tune should net gains.

 

The ram air thing is nice but it was tested a while back and I think you have to be going like 90 mph before it's does anything more than a regular k&n intake would do.

I have the FIPK K&N and it was a waste of money, it looks cool but it was money not well spend.

The best thing he can do is get a custom tune. Before I went with EFI live, I had a 93 octane wait4me tune and I went from 15.5 to 18.5 mpg driving at 85 mph. The extra $5 in higher octane gas more than pays for itself

 

I agree with the K&N FIPK not being worth it, I have one. I had a custom ram air at one time and it was awsome. It took less throttle at 75mph than without ram air. You are slightly off on the ram air. Yes it does take usually 80+mph to build boost, but you are droping manifold vacume from say -10 up to 0 or even +.5psi at cruising speeds. On a regular dyno a ram air may not net big gains but with air being forced in there can be quite a difference.

 

The best modification I have ever seen for gas mileage is my right foot.