25k mile oil change even possible?

[208vette]

I've been reading posts religiously on this site for almost a year now, and have learned more than I ever thought about oil and other related areas... even having oil analysis done to see whats best for my truck.
My question is.... (in your humble opinion of course

) What vehicle/engine would most likely be able to do a 25k mile interval on an oil change, following Amsoil's rules of 1yr or 25k??
I will start off by saying is sure isn't a Toyota out here in the mojave desert...

 

[Pablo]

Actually a straight run vehicle, almost all highway miles would be a great candidate. Read in UOA, a fellow just did exactly that.

 

[TSoA]

Audi cars in Europe with Flexible Service Interval running special low HT/HS Castrol SLX LL-II go 60,000km between changes, with testing.

 

[TooSlick]

A four cylinder, non-turbocharged engine, with modest power output and a large sump. My 2.4L Toyota tacoma engine does very well in this regard, and the 5.5 qt sump was one reason I chose it over the Nissan offering. Here's an oil change formula I've developed in the last year:

Amsoil OCI = (120)(sump-qts)(mpg)(cubic inches/Hp)

Those are the key parameters that determine drain intervals ....The constant of 120 was determined by looking at tons of oil analysis data and reverse engineering the formula to get it to generate reasonable results ....

I've run a number of drains > 20,000 miles using Amsoil and gotten good results. Typically, the only negative impact of running this far is that the oil will tend to thicken up by a grade. So the 0w-30/5w-30 you start with will end up as a 0w-40 or 5w-40. The 0w-30,5w-30, 10w-30 grades are best for running these long drains, due to the oxidative thickening effect.

Tooslick
www.lubedealer.com/Dixie_Synthetics

 

[Patman]

quote:

---

Originally posted by TooSlick:


I've run a number of drains > 20,000 miles using Amsoil and gotten good results. Typically, the only negative impact of running this far is that the oil will tend to thicken up by a grade. So the 0w-30/5w-30 you start with will end up as a 0w-40 or 5w-40.

---

Are you sure they still maintain their first viscosity number though? If it's thickening up at 100c enough to turn from a 30 to a 40wt, chances are that it's cold cranking ability is also now suffering, so I would think a 5w30 would turn into a 10w40, while a 0w30 would turn into a 5w40. I can't imagine it still being able to have as good of a cold cranking number after 20-25k if it's getting oxidation like that.

Thoughts?

 

[Steve S]

Would the oil still be better than the better group 1 oils with 3,000 miles

 

[yannis]

Taken from a comparison test among for 1.6 litre cars in a Greek magazine:

Maintenance Mazda 3 Peugeot Renault Toyota

307 Megane Corolla
Km for service 20000 30000 30000 30000
or 1 year or 2y or 1y or 1y


Km for oil change 20000 30000 15000 15000
or 1y or 2y or 1y or 1y

I know Peugeot and Toyota use synthetic(5W40) for these intervals , i don't know about the others.
10000 miles=16000 km approximately

[ November 29, 2003, 03:51 PM: Message edited by: yannis ]

 

[Alex D]

TS ...... this formula works out to about a 14000 to 15000 OCI for all of my cars.

quote:

---

Originally posted by TooSlick:
A four cylinder, non-turbocharged engine, with modest power output and a large sump. My 2.4L Toyota tacoma engine does very well in this regard, and the 5.5 qt sump was one reason I chose it over the Nissan offering. Here's an oil change formula I've developed in the last year:

Amsoil OCI = (120)(sump-qts)(mpg)(cubic inches/Hp)

Those are the key parameters that determine drain intervals ....The constant of 120 was determined by looking at tons of oil analysis data and reverse engineering the formula to get it to generate reasonable results ....

I've run a number of drains > 20,000 miles using Amsoil and gotten good results. Typically, the only negative impact of running this far is that the oil will tend to thicken up by a grade. So the 0w-30/5w-30 you start with will end up as a 0w-40 or 5w-40. The 0w-30,5w-30, 10w-30 grades are best for running these long drains, due to the oxidative thickening effect.

Tooslick
www.lubedealer.com/Dixie_Synthetics

---