New (to me) Dodge diesel truck, question or two for ya.

[Whoaru99]

Recently was given (for a company vehicle/work truck) a 1998 Dodge Ram 2wd 3500 dually. It has 187K miles on it. It has the 24-valve engine, 5-speed manual transmission, with 3.55 posi/limited slip rear end. It also has a power module and pyrometer added by previous owner/user.

Drove it ~430 miles not towing, not loaded, with most of it interstate driving (with the power box "on") and got 18.5 MPG, sound about right?

Anything particular to be on the lookout for?

Tips/tricks?

Do you use any fuel additives beside anti-gel stuff?

[Valv]

Great truck

2wd 3500 should be around 19/22 mpg interstate, empty, with a 3:55 and 5 speed.

Find the IAT sensor, remove it and clean it with carb cleaner. Do same with MAP sensor. It will improve mileage a lot.

If you try to keep your foot off the pedal it will help with mileage, but it's tough to do it.

Check fuel pressure at injection pump, you might need to replace your lift pump which was THE most common problem on Cummins 24 valve trucks. Not a big expense if you can do it yourself

[Whoaru99]

Excellent!

I'll be checking those two things pronto.

I'm all ears for more....

[lotsofish]

Find out what the "power box" is and what the settings are. It might be for more towing power, so having it on uses more fuel. I'd try running it a few hundred miles with it off just to compare.

[Whoaru99]

The box is a TST Products PowerMax2. +90hp and +250 lb-ft of torque according to the TST HSOforum. The box does not appear to be externally adjustable, only has an on/off switch and a few LEDs, one each for power, boost, and fuel. The boost and fuel LEDs get brighter the more you mash the throttle, as you'd expect. It also has the corresponding TST-modified boost pressure fitting in the turbo housing.

Next trip I take I will run with the box "off" just to compare. I've seen people claiming that lightly loaded mileage sometimes increases with "black boxes" but that's just another question because it's all new to me.

[Valv]

TST Powermax is a fueling box, it will add fuel and give extra power. I would stack it with an Edge EZ which will give you timing also, and will be a huge improvement. I always got at least 2mpg more with the EZ.

Be sure NOT to lug down your motor when stepping heavy on throttle, or your clutch will go "south" in a hurry. Try to keep it at least at 1400/1500 rpm when shifting

[Whoaru99]

Stack the Edge EZ, eh?

I'll have to download the manual, if I can, and check that out. On first pass it looked like the EZ does fuel too, but perhaps you set it for what you want it to do?

Maybe it would be best just to eliminate the TST and go with an Edge Juice with Attitude...it's only a "little" more expensive than the Edge EZ.

Been looking..lots of power goodies. The Smarty looks pretty popular too, but some say it pushes pretty hard.

[Valv]

Yes the Smarty is THE best out there, and it's programmable to which setting you want. I had it on my last 2 trucks and was very happy. An EZ does both fuel and timing but can be stacked with the Powermax.

Whatever you do to the truck remember to start saving for a new clutch, you will get yours to slip quickly with some addons.

You are talking $ 700 to $ 1500 if you do the work yourself.

[Whoaru99]

Hmmm...did more looking. Since this is a company vehicle, not sure I want to push it too hard.

I'm thinking perhaps stacking with timing box for mileage like Quadzilla Max Mileage or Edge Mileage Max.

Then with the $ saved there, I could upgrade to the TST remote control for the PowerMax and get adjustable power levels in ~15 HP increments instead of just (~110 HP with timing) on/off.

So many choices...but does that sound like a reasonable plan?

[Valv]

If you use the Smarty you can program it for many power levels, from just a little of timing, to up to 130hp more, and it's completely undetectable from shops, but beware it's VIN locked, if you install it on a truck it cannot be used on another, and if you sell the truck it has to be brought back to stock, otherwise your programmer is useless (still locked to the old VIN).

I would stay away from The Qzilla Max Mileage, I had one and sold it after few weeks, same for Van Aaken (but I believe they are out of business)

Ez Mileage Max is just a reduced version of the standard EZ which is a mild box, I always had good luck with the EZ, you can probably find one used for around 200 bucks. Good power without blowing anything out, and 2 extra mpg to save fuel.

This would be my choice for you, since truck is company owned. If you want to spend more and get more results try the Smarty, you won't look back. It does also read diagnostic codes, fixes tire size odometer discrepancy, and has a couple other small nice features....but it's 600 bucks.

[LwnmwnMan2]

What exactly are you looking to achieve Whoaru?

I know Valv has done his fair share of towing, we have only used Dodge diesels since 2001.

Two trucks have either 24' enclosed trailers at about 10k lbs every day, or an 8' plow on the front, and the other pulls a 26' flatbed at about 12k-ish 3 times per week.

We don't have any chips or modifications and do just fine. We run automatics, 4x4 and average about 12-13 if we keep our foot off the pedal.

If we're not pulling anything, we can get it up to 18-19, 20-ish if we're heading east across No.Dak.

The best truck I ever had was a 2003 2500 with 3.50 rear ends. I could push 25 mpg out of that thing if I kept it right at 55.

I've got buddies that are pushing 450 hp with chips in their trucks. But as mentioned before, you need to start to worry about your clutch, transmission, whole driveline then, since those components aren't built to handle all the extra torque.

One last thing about your last sentence with the fuel additives. We don't use anything. We don't plug the truck in (unless it's -25) and we've never had an issue.

[Whoaru99]

No specific goal in mind. Almost certainly the truck will not be used to pull anything near its maximum capacity. I'll spend 90% of its remaining miles hauling me, my suitcase, and laptop computer.

The boss went scrounging and came up with some vehicles that other plants no longer had use for. So, he did some wheeling and dealing...and got them. I ended up with the big diesel.

Since this presents a golden opportunity to experiment at a relatively low cost of entry (I didn't have to buy the truck) but will buy the tuners, I figure I'm going to learn a little, try to pick up a couple more mpg, and have a little fun...all without trying to go overboard and wrecking something. I have fully disclosed this all to the boss, and since he's a motorhead too, his words of wisdom were "just don't blow it up".

No plans to race the truck or anything remotely like that, but I do like to feel the pull of a strong engine whether it's in my motorcycle, car, or truck. And, since it already had a box in it, one flip of the switch and roll on the pedal I knew I was hooked...

[Valv]

Your motor has 215hp stock, with a Edge EZ at 60hp, 6 new larger injectors at 80hp extra. Add a better air intake and open up exhaust will give another 10hp.

You are at max capacity before you start hurting your clutch. If you had the 6 speed it would have been better since the clutch and flywheel are 13" instead of 12".

You will not blow up the motor guaranteed, but you will kill all it's attached to it.

One upgrade you should do regardless is your lift pump (the electric pump that transfer fuel from tank to injector pump), since on 2nd gen Dodges it is installed near motor, it has a long way to "suck" all the way back from rear of tank. Result is pump will die soon, the VP44 (your injector pump, very expensive) will draw some fuel too but since it uses the overflow diesel to cool itself, it will starve, overheat, and BAM, leave you SOL.

There are few options, from an easy (and relatively cheap)relocation using a Holley Blue (or Black) pump nearby the tank, to different others more expensive and more sophisticated. Regardless of which one, you should replace it asap.

If I was you I would add the following enhancements:

A lift pump replacement, (Holley or FASS)

Edge Z or Smarty

Pensacola Diesel stage 2 injectors

BHAF air filter

This will put your motor almost to the same HP as a current model (around 325hp), and it will be a good upgrade that will cost less than a grand. You will probably be able to beat a Mustang or definitely any ricer (unless they have turbo).

If you "motorhead" guys want to talk more power then you will have to drop a lot more cash. There are trucks out there that are street legal and driving normally which can produce in excess of 800hp

[Whoaru99]

I'll have to look into that lift pump situation. Due to budgets getting close at the end of the year, not sure there will be a possibility to replace/upgrade the lift pump until December/January timeframe.

I'd pop for the performance enhancements, but for basic reliability/maintenance stuff that I can't really take off, the company will have to foot the bill there.

[Whoaru99]

Anyone with experience with the Quadzilla XZT+?

Since I haven't been able to yet find a used Edge EZ for the truck, someone mentioned the XZT+ being comparable to the EZ in terms of power gains and mileage, but with more features and more tunability with different maps/cals that can be loaded via USB. And, it's about $250 new vs $400 for EZ.

Thoughts/opinions?

EDIT: Checked fuel pressure, and for now it seems to be OK. About 13 PSI at idle, 11-ish under normal driving, 8-ish with the hammer down. I understand that 10 PSI or more under all conditions is optimal, correct?

Looking at maybe AirDog 100 for fuel system upgrade if boss OKs it.

[Valv]

Excellent choice with the Airdog. yes your fuel pressure is very good.

Without any "enhancements" you can get as low as 5 or 6 psi at WOT. I believe stock is 10 idle and 4 lbs WOT.

I had an XZT, I liked it but not as much as the EZ, I had slightly better mileage. You can fond a used EZ anywhere for around $ 150/$200 be sure to get the correct year, there are 3 models for 2nd gen 24valves.

[Valv]

Send me an email, I might have found you something

[Whoaru99]

Thanks much!!