So I've been reading all about the 600 mileage issues. There is a poll that asks what milage 600 owners are getting, so for comparison here is one that asks what mileage 555 owners are getting.

I found a new 555 silver sport and want to pull the trigger, but can the fuel issue in the 600 be solved with a box? Big question to answer since there isn't another 555 set up the way I want it anywhere near here. Houston, TX.

David
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The truck I found: 2004, silver, sport, 555, auto, cloth (in gray) LWB, 2wd, 373, QC.

 

Go with the 555 you will not be disappointed. I wish i could find a 555 the way i like. It sound louder and as i found out today gets way better mpg. Good luck.

 

Just as an exercise, looking at the numbers from the two polls, with the 555 averaging 19mpg, it would burn 5263 gallons of fuel in 100K miles.

The 600 (or any thing else for that matter) averaging 15mpg would burn 6666 gallons of fuel in 100K miles.

Thats a difference of 1400 gallons. What would that cost where you live? That's only about 2250 bucks around here... for now.

In reality that comes out to $68 a month if you do 3000 miles a month. (Someone check my math.) Is it worth worrying about? How good is the 600???? Really?!?!?

 

555

 

Pull the trigger and get the 555.

MikeyB

 

I see alot of people getting great milage out of a 555, but I am only getting 15.5 to 16.5 no matter how I drive it. I am about 75% city and 25% highway. I have driven a little highway and have gotten close to 18.5 but definately not 20-21. The guys getting 20-21 must live in the plains area with no hills. I am in the piney woods of east texas that is one continuous hill. I am adding an AFE and exhaust some time this month so I am curious as to what effect it will have on my milage!!

Brad

 

I was getting 19.?/mpg (calculated by hand) before the bed cover and now with the bed cover it has jumped up 2+/mpg (calculated by hand).

 

I have yet to get less then 18.4MPG (all around town) in my late 04. On the freeway if I keep the tack at 2100 71ish I'll pull down 21.5.......... The truck only has 4700 miles on it so far.... I"m very happy with it.

 

My worst mileage so far has been 15mpg from towing a 6k lb trailer for 600 miles running 75mph most of the way.
My best is 22.1mpg running 65mph.

MikeyB

 

I have the 04' 555 with ~ 5700 miles. 6 speed.

I drive 70% hwy and 30% city.

On the freeway I rarely go under 75. But don't usually cruise over 80 (unless I'm passing), since the truck starts to vibrate pretty badly over 75mph...

My last tank avg. was 18, but every tank before that was ~ 16 to 17.

Things are going up and I hope they continue to, b/c I would like to avg. ~ 19.5 like my 02' Duramax (and with that truck I was always cruising ~ the 80 to 85mph zone, since the ride was so smooth with no vibes)...

PS, note, all my Rams fuel so far has been with the Winter blend (picked up the truck in Dec. 04). So, I know that robs some fuel economy...
Boss

 

Just got off the phone with a dealer here. He said that the 600s are losing 3-4 MPG over the 555. He said that there may be an injector modification that can get you better mileage. (Aftermarket, I think, but through their service dept. for warranty.) Will post more when I hear back from him.

 

I average around 14 mpg towing a 3500 lb car on a 16' car hauler and if I keep the mph to 72 or less it's as much as 21.4 mpg, but with combined interstate and rural driving, 18.2 or so. Go over 75 mph and the mpg goes down noticeably. I love my "555" personally. Just wish diesel prices were back around $0.83 per gallon when I bought my 98 RAM 2500 CTD 4x4 12V in December of 1997. I'm currently at 13k miles and counting. 3rd CTD and I've loved them all !
Greg

 

Update on the modification:

The dealer (actually the GM of the dealership) said that he spent a bunch of dough on mods to his own truck. He tows a 3 horse trailer w/living quarters and 2 horses. He says he gets about 4MPG better mileage now than before the mods, but the one mod he did that gave the most benefit was sending his injectors out to Dr. Performance to have them polished and tuned somehow. He thinks that out of the 4 mpg he gained with all the mods, the injectors provided most of it, or about 3 mpg. Cost: About $1500.00 dealer installed, if memory serves. I think I remember right that he said he has spent $4K+ on all the mods.

For those of you who would like to know, there it is. That said, $1500.00 will buy a few tanks of diesel.

HTH
David

 

Just bought a new 555 (lucky to find one the way I wanted it). Averaging 17 around town, and 18.5 highway with only 1,100 miles on it. I expect to be around 20-21 with bed cap and break-in.

I drove a 600. It is quieter, and shifts smoother (6 speed). Did not notice any real power difference. I opted for the 555 for better mileage. It is still pretty quiet after it warms up. I am happy that I got the 555. Better hurry if your going to do it!