Once again, synthetics and oil analysis

[newbury]

Numerous discussions on the benefits of synthetic oils and oil analysis.

My 2002 F350 7.3 is advised to change every 5K miles.
I switched to Rotella T-6 from quality dino oil last fall. Primarily for the "ease of starting when cold" which I had read about. Well that worked GREAT.

I also changed over my '88 Ford 7.3. Starting when cold issues about went away on the '88. On the 2002 it never even cranked slow ALL winter and I never plugged it in.

One oil change takes 15+ quarts, or about $82.50 at current walmart prices, plus $10 for a filter.
One oil analysis costs $19 plus postage, and tells me far more than if my oil is good for more miles.

Well, just got my oil analysis back from Blackstone.

GEORGE: You didn't put the time on the oil for this sample, but it looks like 6,922 miles were added to the
engine since the last report. Assuming that's how long this oil has been in use, everything still looks great.
Iron is a little higher, reflecting the slightly longer oil run, but metals are still reading at or below average
levels, and there are no signs of mechanical issues developing as far as we can see. The small amount of
fuel we found in the last report has gone away, and no other contaminants were found. This oil can definitely
go longer. Check back in ~3,000 miles.

So I'll check back in another 3K.

After I establish a pattern I expect I will be able to run it 10K miles between changes, just like I do my '09 Jetta TDI.

So $20 on an oil analysis saved me $80 on oil.

[Buckgnarly]

How many miles on the 88? I have been thinking about switching over to syn on my 89, but it's got 255K+ (odometer has been broken) on it. I run Rotella 15-40 Dino in it now, any help in cold starting would be good for it!

[newbury]

How many miles on the 88? I have been thinking about switching over to syn on my 89, but it's got 255K+ (odometer has been broken) on it. I run Rotella 15-40 Dino in it now, any help in cold starting would be good for it!

Only about 190K.

[Copperhead]

I run 11,000 between oil changes on my Jeep Liberty Diesel without bypass and such. No issues. I run my Detroit 12.7L to 25,000 with bypass with no problems. Considering moving that one up to 30,000 miles and see what the results are. Virtually all synthetics, regardless of brand, are good for a minimum of 7,000 miles and usually more. Since my Detroit takes 38 quarts per oil change and two Donaldson ELF3998 filters at $20 a pop, it makes sense to go further with the oil drains. I have been using the Delo 400 LE 5w40 synthetic from Wally World that has had a price of $19.98 a gallon since last fall.