Heath,
I have a comment and a question. Comment, I recently switched from Rotella T to Amsoil Diesel & Marine and couldn't be happier. After I made the switch my average fuel economy jumped from around 17.5 city to around 22.5...I thought I hit gold.
Now the question, my fuel economy finally setteled around 19.5 city. Don't get me wrong, I'm happy for the two or so extra mpg's but is this a normal fluctuation after the initial switchover? I've already changed my fuel filter in hopes it was just a coincidence but it hasn't jumped back up to 22 mpg's. I'd appreciate the input so I know if I need to look for other issues affecting how my truck is running.
Another question, is the Diesel & Marine the best AMSOIL product for me to use?
When it comes time for my next oil change I'll be contacting you for a resupply. I'm also looking at tranny and diff fluid upgrades as well.
Thanks,
Beaker

 

Hi Beaker,
To be honest, that big of a fuel mileage increase is rarely seen. You might at 2-3% increase which is good, but hardly noticeable. Your first improvement was 28%!! Then backed off to 11.5%. That is still quite good. I'm amazed at that actually.
As for why it was better right after the change and then backed off...hard to say. You usually don't see that fluctucation.
I have an 05 quad 2500 and the best I've ever gotten in the summer is 20.5. My digital readout says 23-24, but when I measure it, it's a bit less.
Since you are in the warm south, I don't we can blame it on different fuels(#2 vs. blend).
Sorry I don't have a good answer for you.
For any truck 06 and older, the diesel and marine is the product of choice.
As for supply, sounds good, you know where to reach me

 

send me the info to please heath

 

send me some info to thanks

 

Heath, what would you recommend for my front and rear pumpkins on my 06 F250? I'm coming up on 60k miles and need to change the fluids. Thanks.

 

Yea Heath, I thought the increase was a little optimistic as well but I was just hoping it was the real deal. I also know the overhead digital readout is a few points to the plus. I keep receipts from fuel ups and write the mileage on them and after a few months calculate and log them. I typically averaged around 14-15 mpgs when doing the math before the switchover but I haven't calculated my recent receipts so I don't have actual mpg on the new motor juice. It's just easier to pay attention to the overhead readout and guage how I'm doing. I will tell you though...count me in as a loyal AMSOIL user from now on because my engine runs smooth as butta!
Thanks for the input.

 

I believe the Fords all want 75/140 in the rear now. Seems they had some troubles in the past with the 75/90 and losing rearends. So the severe gear 75/140 is the pill of choice for that. You could also run it in the front, but the 75/90 is probably more appropriate.

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You bet. Always good to see another happy user.

 

You said Diesel and Marine in 06 and older. What about an 08 Cummins? The Premium API or Series 3000? Or will the Diesel and Marine work. I am getting ready for my first oil change since I got the truck back from the shop. Also, what Tranny fluid? May as well ask while I'm here.

 

For the 07 and newer you need the CJ-4 rated oils. That'st the premium 5W-40(DEO) or the 15W-40(DME).
If you have removed your DPF, then you probably could use the older stuff, but the newer is what's called for in your manual.
The tranny takes the universal atf(ATF).
Need help getting it, just give me a ring.

 

Can you send me some info.