was wondering if anyone noticed a gain in mileage from adding synthetic oil to their motor and if adding it to the differentials gained anything or if it was noticed? I know it's time for me to do a complete change in mine so was looking for info and what other people would do if they were doing it

 

I gained a half MPG on the motor and on my rear diff my temp went from 190 down to 160 when towing heavy ...well worth it

 

On our own company truck, I noticed the engine to get quiter, especially after it has warmed up, the tranny temp dropped about 25-30 degrees under a load, but I can't tell you an actual number on the differential because I don't have a gauge on it.
Mileage is always a difficult to one to calculate on this because of so many factors come into play. The biggest gain of course is the added protection and extended drain intervals.
Kenny

 

For me, I found that so many other factors have a bigger impact: towing/empty, city/highway, headwind/tailwind, SPEED, etc .. that without some kind of controlled test it would be hard to actually put a number on the MPG improvement. but with synthetic (Amsoil in my case) in the engine, transfer case, tranny, and both diffs, you can FEEL that the truck rolls easier especially when the truck is unloaded. It takes less throttle pressure to get it rolling, and coasts faster & further when you are slowing down for a stop sign or red light. Whether I got .5 or 1.5 mpg improvement, I dunno. But it adds up.

A little better mpg for syntheic oil, a little more for a built tranny & ATS TripleLock converter and lockup commander, Smarty on economy mode, RV injectors, Amsoil air filter, drive 55mph on the interstate,etc - and I've managed to hit 25 MPG (calculated!). Yes .. it is a 4x4 2500 Quad cab WITH mileage killers like running boards and bug deflector!

Add to that the extended drain intervals (with dual remote filters & oil analyis) I spend less money on oil changes, less time under the truck, have less waste oil to dispose of, and the best part ..... It's Made in America!

 

thanks guys just looking into what routes to go. I know it's time to do the diffs on the truck cuz I have had it for a while and not sure when it was done.

 

I saw 1 mpg increase when I went from dino 15w40 to Amsoil 5w30 HDD.

 

Hello PropectorTim. I'm also a retired MSGT and an authorized AMSOIL dealer. I live in Utah. My first assignment in 84 was to Blytheville AR. Just north of ya.

Really wanted to discuss your tranny upgrade. I have an 02 with 76k miles on it. I pull a 33ft 5th wheel toyhauler and am getting concerned about my tranny. Havent had any real issues yet, but seems to want to skip a little when going into overdrive with a heavy pedal.

What tranny did you decide on and why? There is so many ads out there, that I dont know which to trust.

I put this here because I cant PM you until I get 10 posts??

 

I lived in Colorado Springs and I'm a TDR member. I went to the first 2 RMTDR/ATS meetings at ATS in Denver, and besides having a good time looking at other people's trucks and drooling over performance goodies, I was really impressed with the technical discussions, their shop and their products.

On my next-to-last trip moving to Memphis and towing a fully loaded trailer, I noticed that even with the cruise control set and the speed constant, my tachometer was going up and down with the hills. Something was slipping!

As soon as I got back to Colorado, I took it to ATS for a new tranny & Triple-Lock converter. A paycheck or 2 later I added the lockup-commander and Mag-Hytec DD pan. The truck had 115,000 miles on it then; 166,000 now. No problems. I will admit that the truck has a MUCH easier life now that I've sold the 5th-wheel and ATVs and only make it back to Colorado about once a year.

Bottom line: I like my ATS. There are other high-quality, performance tranny shops out there with a lot of happy customers - and some of them ARE less expensive. I think all of them are WAY better than stock, but then I'm just a customer, not a transmission expert.

 

I put in Amsoil 15-40w HD marine , I gained maybe .5-1 MPG , I had heard for yrs that it should leak more , I have some leaks , but not more than dyno oil [ 1 qt - 3,000 miles ] , I also noticed that my oil pressures are higher , both cold & warmed up [ 2-4 psi ] . I have most of the fluids for everything els , but waiting till repairs / upgrades before putting in , axial seals , built trans ect .
I just put in a Amsoil Dual By Pass , 15Ea system , the oil had 4,200 miles on it before the bypass , the picture is after the bypass & 100 miles .
I plan on changing oil when analysis says to .