Oil change interval algorithm

[Genie47]

Like the TV series Numbers, everything can be mathematically determined.

 

OK visit this page here: http://neptune.spacebears.com/cars/stories/interval.html

 

Yes they are the same guys that are doing the Amsoil vs M1 ongoing study on the longevity of synthetic oil.

 

Firstly, you need these online calulators.

 

Fuel economy conversion calculators:

 

http://www.projects.ex.ac.uk/trol/scol/ccfuel.htm

 

OR

 

http://www.sciencemadesimple.net/fuel_economy.php

 

Engine displacement conversion calculator:

 

http://www.4lo.com/calc/literstocid.htm

 

Finally, miles to km calculator:

 

http://convert.french-property.co.uk/

 

So assuming I am using RP. RP has a TBN of 8.0 (actually most good PCMOs have a TBN of 8.0 and most HDEOs have 12.0)

 

My engine is a 1.4L so that translates to an 85cid engine.

 

The fuel economy I'm getting is 13.5 consistently.

 

The engine churns out 94HP.

 

My sump capacity is 3.8qts. (I throw in 4qts actually)

 

Using the Kublin method, I get an oil change interval of: 8742miles

 

That is equivalent to: 14068km

 

Wow! My oil can go so far!

 

By using an oil with a TBN of 12.0 like Amsoil or Schaeffer's Supreme 9000 5W40, this bumps the OCI to 21101km!

 

I wouldn't dare attempt the Heidelbrecht method. Very complicated and you have to measure the make up oil you put it. I may kiam but won't kiam until this extreme!

[Cyberet]

Wow.. using RP, mine only last 5543miles

[Genie47]

Slightly short of 10k.

[Cyberet]

no wonder alot of the mazda guys commented RP after 7k gotta change liaoz

[Genie47]

Mazda 323 use 3qt of oil only, that is the reason why. The other car I'm worried about is Latio. Also 3qt oil in total. Sunny also 3qt oil. Better use oil with good high TBN to bump things up.

[Cyberet]

hehe.. luckily i did not stock pile RP

lots of M1 sitting, waiting for the current RP to hit 8k km before i do a UOA

 

in fact, 3 quarts is abit too much, over the F mark on the dipstick by abit. 2.7quarts would be perfect.

 

Would LC help in any way in extending the life?

[Saaber]

yes it does.

[DarkLord]

Oooh... Want to send together? I got a bottle here for analysis also.

[Robin]

u calculated for M1 liao??

[Cyberet]

8314miles for M1

[Cyberet]

i got a month more before i hit 8k km. i'm passing to ryan to send. you?

[Robin]

heng arh...

[Furrynadz]

so much hassle

i just buy 18L drum and change every month

[Genie47]

18L not drum. Pail/bucket. Using Delo issit?

[Furrynadz]

nope

castrol rx super plus

[Nine_eleven]

based on a 1.6l altis on M1 3.8quart... i can change my oil at every 12,147kms... so a 10k oil change is conservative lah.... not bad lah...

 

tho, its still a theoretical figure...