SCCSURF

I'm coming up on 50k miles and wondering if I should switch to synthtic oil or stay with regular oil. And if so which synthtic oil to use. I've put Amsoil in the tranny, any thoughts?

NavyDood

how many miles a year are you driving?

SCCSURF

around 17k, I'm almost at 50 and have had the truck for three years now.

NavyDood

I drive right at 23,000-25,000 miles a year. I run Amsoil AME 15w-40 and Amsoil EaO80 filter. Last oil change I went 1yr 3 months/28,000 miles before changing the oil. Analysis was good. It's a no brainer for me due to the mileage driven. My 04 is a lot easier on oil than the 04.5 and newer trucks though.

walker1

Sorry to hijack. Do I have to run a bypass to get the extended oil change interval, or just change my filter every 5000 miles and send away for analysis?
TIA

Nate-03 D

I run the Amsoil 15w-40, I go 12k miles between oil changes. I run the Fleetguard Stratapore filters and change them at 6k miles. You don't necessarily need a bypass but in order to really extend the intervals it'll help.

Thundercraft

The EAO80 filter is good for 25,000 miles/1 yr.
With a "regular" filter, then at OEM intervals.


With a bypass, he most likely wouldn't be required to change the oil for a long time.

walker1

I run a donaldson EL filter, and just Dino oil. I think I might try amsoil only if I can go extended intervals. It's hard to justify when I get oil for free from work. Right now I do oil changes around 2500-3000 miles.

SCCSURF

If I run the Amsoil without the bypass what would my intervals be in changing my oil? 10k?

iml84bed

I had the amsoil bypass filter system on my truck and took it off, I was also an amsoil sales person and told them to stick it. They claim all these unreal claims like never change your oil, only change your filters and top off your oil. Their claims are all crap, I used it, with only 20k miles on the oil with a filter change at 15k, both the amsoil bypass filter and a donaldson full flow filter, I sent in my oil analysis and the resultes were to change oil and filter immediately. My advise is do not rely on extended change systems, buy a good synthetic and change your oil every 7500 miles or 5000 miles if you are in heavy dust or heavy pulling situations on a regular basis. This is just my opinion and I wanted to share my experience, good luck with what ever you choose.

Dieseljunkie

Depends on which maintenence schedule you follow from the manual.. With Dino oil, and a standard filter, I followed schedule A, which is 15k miles between oil changes.. When I went to Amsoil with and Amsoil filter, I have uppped my oil change interval to 30k miles.. And with the last oil analysis, at just before 30k miles, the oil was still fine to use, but I changed it anyway..
Scott

SCCSURF

If you're not using amsoil which synthtic oil are you using? Thanks for your opinion. I'm not looking to use a bypass system just looking to switch to a synthtic oil now that I'm at 50k.

I used to change my oil every 3k with just a stock oil filter and delo400, but I switched to 5k when I hit 40k. I live in a high altitude and very dusty area.

.boB

Synthetic oils have two performance advantages over dino oil. 1. Longer drain intervals. 2. High heat management.

Oil is heated predominantly by rpm's. Diesels don't see heat high enough to matter.

Standard drain interval with a dino oil is 5K-7.5K miles; every 3K is only recommended by people who sell oil and oil changes. And your granpa, because it's always been done that way.

AFAIK, there are only 4 true synthetic oils on the market, and Mobile 1 is not one of them.

SCCSURF

I just can't imagine not changing my oil at least every 5-7k miles. It seems pretty hard to me to think the oil is going to keep it's properties for 30k miles with everyday driving let alone towing, high heat areas, and traffic. I'm a mechanic on large diesel engines and we change our oils out at a min every 500 operating hours. Thanks everyone for their opinons.

.boB

I think you're right. I don't care how much you filter the oil, the additive package just is not going to last for 30K miles.



This is my last oil sample results. The column on the right is after 13K miles of use, on Valvoline Premium Blue. I didn't intend for it to go that long, but an emergency came up and I had to hit the road. But, after all those miles the oil itself held up pretty good; viscosity, flash point, and TBN were not bad at all.

The middle column was a sample I took right after changing the oil. I wanted to get a baseline to compare the next change to. But I don't think those numbers are correct, they don't make much sense.

The column on the left is after 6K miles. I was going to let it go to 7,500 miles, But I had a long road trip coming up that would put me over that number. Anyway, at 6K miles you can see the oil is still in excellent shape. Additives, TBN, viscosity, etc, all look good. The oil could easily go 7.5K miles. But no way could it last 30K. Or even 15K.