I believe the headlights are different in 06, they have a reflector at the bottom, 07-08 don't have that...I think.

MDS doesn't really give a 'drone', its more of a constant pulsing...it can get annoying, but I'm almost used to it on mine with now a dumped flow-pro.

You also have gone from a solid front axle truck to an IFS, so you'll have all that fun stuff an IFS is notorious for.

 

yeah, I'm not sure with the headlights, I'm just going from what I see when I shop around online for headlights, they get grouped 02-05 and 06-08.
Fuel wise, I'm pretty sure the Hemi's need minimum 89 octane.
From posts I've read here, I think the stock exhausts sound ok with the MDS, but some aftermarket exhaust will give a much worse effect with MDS and other systems are good at sounding the same when the MDS kicks on. You'd have to do a search on here for more details on that

 

I have an '06 and the only difference in the headlights is the reflector along the bottom edge on the '06s, the '07 and '08s do not have that. I really can't tell ya much info about the 5.9 becaue I have a 4.7. I just recently got a SC 3865 for my truck and I run the 91 performance tune on mine and believe it or not can actually justify the cost of running the higher octane gas with the 1.5 mpg gain I have gotten. Not to mention the pleasure I get from the much better performance.
I have read that alot of people who get the SC 3865 will turn their MDS off with the tune and still get basically the same mileage as they were getting before. Once again I can't tell ya much about that, just what I have read, because my truck doesn't have MDS. There are a lot of good threads and stickies on here to better answer your questions but one of my top suggestions I would give is to get yourslf a SC tuner. I could not believe the difference in the performance of my truck after installing it.

 

The O/M says 91 is preferred, 89 acceptable, 93 not recommended.

 

The owners manual for 08 says that 89 octane is recommended. Most cylinder failures have occurred in trucks run on 87 octane. Detonation (even that can not be heard) can reek havoc on pistons and valves.

 

So SUPERCHIPS over hypertech and diablosport?

 

So pretty much MIDGRADE? DEF NOT 87 and DEF NOT93 PREMIUM?

 

The SC was the first tuner I purchased so I really can't talk hypertech or diablo down. All I know is the difference between now and before is night and day with the SC. I really relied on the suggestions from members here and on other sites and quite a bit of research on my own and ultimately decided to got with the SC. And I can honestly tell you I have NO regrets.

 

I had a '98 1500 RCSB 5.9 4x4, 5" of lift, 35" tires. I have an '04 1500 QCSB Hemi 4x4, 4" of lift, 35" tires.

1) You should see a 20-25% gain in fuel economy (non-towing).

2) The Hemi will pull better, especially when accelerating to pass and getting on the highway. Despite having 40 more lb/ft of torque however, the Hemi makes most of it's power in the mid/upper RPM range. Down low, just starting off, there isn't much difference, in fact I might give a slight nod to the 5.9, but up after about 1600 RPMs, the Hemi, no question.

3) Day & Night - the 46re was the big reason Ram trucks had the reputation for having the best V8 engines on the planet mated to the worst transmission. The 545rfe was the first tranny designed by Daimler (Mercedes) for use in V8 trucks and the technology is light years ahead of the 46re. It may not be bullet-proof, but for the first time Dodge has a light truck transmission that is at least on par with those offered in GM & Ford half ton trucks.

4) Exhaust (especially if you ditch the very restrictive factory "Y") is a good upgrade, as is a tuner. The CAI by itself doesn't do much, but will compliment the exhaust & tuner.

5) The two biggest differences in the '06+ 3rd Gens from the '02-'05 3rd Gens were the addition of MDS to the Hemi (although most see no real benefit from it and I'm no fan of it in a truck) and the coil over front suspension replacing the torsion bar fronts in 4x4 models. I kinda like the old torsion bar system, myself. You can "adjust" front end ride height up to about 2" with no additional parts and there is a good bit more room to clear a wider tire than you have with a coil around the shock. However, grocery getting ride comfort is a good bit better with a coil over system. Aside from some cosmetic changes (head light/tail light/etc., the '06s and '07-'08s are identical).


Although your "book" says 89 octane recommended but 87 is ok, this engine has a compression of almost 10:1 and I wouldn't use 87 in an engine with a compression that high. Also, every Hemi with a cylinder or multiple cylinder failures I've seen (aside from the '03s which could snap it's comparatively weaker springs) have been in engines where 87 octane was used predominantly. Stick to the 89 octane gas, unless you are running a tune that de-tunes the truck to make 87 ok, or a performance tune that requires 91/93 octane...

 

4. But is it true that with the MDS, aftermarket exhausts sounds horrible because of the switching back 4cyl to 8cly?

5. So If I JUST put a 2" leveling spacer in the front, I dont need to do anything else, such as replace shocks, front suspension components... etc? Also, whats the largest, widest, tallest tire I can ran on the STOCK 20" wheels with just a 2" spacer?

6. Ill stick with 89 midgrade but def DO NOT run 91/93 on a stock hemi with no tuner?