I just got my new Ram 1500 Hemi, 2WD and am looking to do 2 things; minimize wear on moving parts and slightly improve gas mileage. I am thinking of putting synthetic gear oil into my 3.92, non-LSD rear end and synthetic ATF into the 5-speed auto trans. I will also be switching to Mobil 1 5W-20 if I can ever find it on a shelf. Has anyone done these before and if so, was there any MPG benefit? If it was long enough ago, how are the rear end and tranny holding up?

On a similar note, is anyone running Water Wetter or Purple Ice in their coolant? Satisfied with it?

 

Autozone has the Mobile 1 5/20 at about 5.79 a quart.

 

Yeah, I just found some at Advance Auto Parts for 4.44/Qt. Thanks.

 

WalMart has M1 in 5qt jugs for $19.

Also, as far as I know there isn't any ATF available that meets DC requirements other than the MOPAR fluid. I think it is already synthetic.

 

Amsoil has sythentic tranny fluid for $8/qt.
This is from their site--

Synthetic Universal Automatic Transmission Fluid
Meets the requirements of most automatic transmissions. Eliminates confusion, mis-applications and lowers inventory requirements. Delivers maximum protection and is excellent in demanding environments such as towing, hauling or commercial use. Lasts longer than conventional oil for extended drain intervals. Saves time and costly maintenance expenses. Superior hot and cold weather performance. Improves efficiency and typically reduces operating temperatures by as much as 50°F. Performance specifications include: GM DEXRON® III, Ford MERCON® & MERCON® V, Chrysler ATF+ through ATF+4, Allison C-4, Cat TO-2, Voith G-1363, ZF TE-ML 14C, Toyota Type T & T-IV, Mitsubishi/Hyundai SP II & III, Honda Z-1, Mercedes Benz 236.6, 236.7, 236.9, BMW 7045E, SAAB 3309, SHELL 3403
(Not for use in CVT transmissions)

They also have 5W-20 motor oil for $5.20/qt. Here's the link for it -- https://www.amsoil.com/storefront/xlm.aspx

I've been using Amsoil for almost a year now. I am using ASL 5W-30, rated for 25,000 mile drain intervals in my '03 Caravan, and my previous truck, a '96 Chevy k1500.

I have almost 19,000 miles on the van oil with only one filter change at 15,000 miles so far. I don't think it's improved power or mileage enough to tell, but I don't have all the mess and time with changing oil every 3000 miles like before. The wife and I both drive over 50 miles round trip everyday to work, so I was changing oil on both vehicles about every 8-10 weeks.

 

The rear is already filled with synthetic.

Personally, I'd only stick with the factory fill for the tranny. The factory Mopar ATF is as good as it comes.

Motor oil, any good synthetic is fine. I really don't think you'd get a difference between some of the boutique brands (Amsoil, Royal Purple, etc) as the mainstream such as Mobil 1 and Castrol Syntec (even though it really isn't a true synthetic). I personally don't like the idea of a 5w/20 weight oil so I'll stick to my 5w/30.

If MPG is a factor, well, about the biggest mod you can do is tape an egg under the accelerator! Seriously though, keep the revs and the speeds down and you'll see your biggest mpg improvement. Best MPG I've gotten was at 65mpg with cruise set. It was about 19mpg per pen/paper over 300 miles. Relatively flat and cool outside.

 

How do you keep friction adding contaminants from entering your oil over 19,000 miles? At most DC says you need to change your oil every 6K. Sounds like a huge risk for getting into a hassle with your dealer if something happens to the motor.

I would also hate to tell them I'm using a trans fluid that says "Universal" on the bottle instead of ATF 4 as they require.

 

You'll not gain any noticeable/measurable MPG with the fluid swap. Maybe a couple (and I mean a couple, as in maybe 2) of extra miles PER TANK, but not PER GALLON.

 

I don't really understand your question about friction adding contaminants. Can you clarify that please?
As for the ATF, Amsoil's website says their ATF meets the DC spec for ATF 4. I included that in my original post.

Don't take this the wrong way and think I'm pushing Amsoil. I'm not a dealer or getting any kickbacks from anybody for promoting their product, but any company that will guarantee their product like they do impresses me.

What sold me on the 25,000 mile oil change was the fact that their oil is as cheap or cheaper than Mobil 1, and Mobil 1 at the time didn't recommend extended drain intervals. I didn't just read their website and place my order. I contacted several people who have used their stuff, and did a lot of research before switching my stuff over.
Will I switch my '05 Ram 4x4 Hem? I dunno yet. Will wait and see.

 

Fuel and airborn particles passing through your intake will eventually contaminate your oil. How much depends mainly on your driving habits and driving environment. It's possible that 19K is ok, but you won't know unless you do an oil analysis to determine how much contamination is getting into your oil.

The primary concern I would have is that Amsoil is not carrying the warranty on your vehicle. The manufacture is and they have set minimum requirements. Many use the reasoning that they are safe because the Magnuson-Moss Warranty Act says the manufacture has to prove that what you did caused the damage. I also think Amsoil uses this as a marketing ploy so you feel confortable using their product. However, I have seen many instances where warranty repairs were denied and they didn't prove anything. If they take that stance, you only recourse would be to take them to court. You might win because of the Magnuson-Moss Warranty Act, but it will likley cost you more in legal fees than what your vehicle cost.

When talking to others, including me, people will often defend what they use. Often more vigorously the more they spend. Of course, this is all just my opinion. I use Mobile 1 and will only say I haven't had any problems with it. I'm sure even that is not needed. Regularly changed 80 cent dyno oil should be more than adequate to preserve your motor for as long as you want to keep it. I have a car now with 198K that has seen nothing but dyno oil, and doesn't burn oil. I've never had an oil related problem with the 30+ vehicles I've owned and usually get rid of them when they otherwise start falling apart. Most have seen nothing but dyno oil.

OK, off my soapbox.