the oil topic comes up alot so i thought i'd put this together


What viscosity to use.....

All I6 OHC cam engines up to and including the EL have a recomended oil of 15w40, the AU and on I6 including twincam are 10w30


why use thinner oil??
these engine are built with tigher clearences then the older engines to enable them to use thinner oil. the up side of the thinner oil is less oil drag on moving parts, transalting to less energy wasted trying to over come this drag. thinner oil is also easyer to pump through the engine and on start up every thing is oiled sooner.

this all means less wear and better feul economy.


Why change from recomended??
for the most part you should never change from what is recomended for your engine. the only thing you achieve is more wear on start up and more feul consumption.

If you are having problems like oil consumption with the recomended oil, it may (but not always) be helped by useing the next thicker oil.


what the numbers mean!!!!!

this is one thing people don't seem to understand.


5w50
10w50
15w50
20w50
one thing those all have in common is at operating temp they are ALL THE SAME THICKNESS

from the top of the list the get thicker WHEN COLD as you go down the list.

the first number is the weight of the oil when could is the first number.
the second number is the weight when hot.

an explanation of the second number......
the seond number is the hot wieght, with a 5w50 the oil starts out as an SAE 5 when cold but it only thins out as much as an SAE 50 would when hot.

the further apart the numbers are the more constant the thickness of the oil. because it starts out thinner.





here are a few threads on the subect of oil (a small selection from the many we have)

forums/viewtopic.php?t=26612&highlight=oil
forums/viewtopic.php?t=26256&highlight=oil
forums/viewtopic.php?t=23638&highlight=oil
forums/viewtopic.php?t=17728&highlight=oil
forums/viewtopic.php?t=17197&highlight=oil
forums/viewtopic.php?t=15158&highlight=oil

Last edited by tickford_6 on Thu Jun 13, 2013 9:06 pm, edited 7 times in total.

does that mean the penrite HPR15 (isnt it 15w60?) is to thick?

yes

good work!

so what would you recommend? ive been usin that for a fair while, would it be worse to keep using it or worse to change to a 15w40. in which case, whats the best in that range? dont wanna go to expensive. and fully synthetic isnt well suited to older engines is it? or even changing from semi to full synthetic is bad isnt it?

i agree 100% but providing your clearences are as tight as they are when new.. obviously after 10 years or say 250000kms your clearences will not be as tight.. this will also depend on the way you treat your car (driving habits,servicing etc) we can only wish that our engine clearences will be as good as new..
if so we would have engines that would never wear out!!
thats my opinion...

im gettting my bottom end rebuilt and have acl pistons is it fine after i run it in to use penrite sin fully synthetic 15w 40?

that wear can be judged by the amount of oil consumption and a simple oil pressure check. if there is no or little oil consumption and the pressure is still within limmits there is nothing to be gained and feul economy to be lost by using thing thicker oil

what sort of fuel consumption are we talking about here? cause mines is crud. could it explain crap consumption stop start driving but fine consumption cruising on highway?

would you recommend i switch back to a 15w40? ive been runnin HPR15 for 30,000km or so i think.

best to stay semi synthetic or go full? in your other thread u said motul8100 15w40 for your engine whats that worth? or should i go a fuchs if they do 15w40?

its an 1996 ef2 I6 mont, with 126,000k's (trip comp susually sits on about 17L/100km mixed driving)

fuchs recommends:
TITAN Performance Plus
A high quality mineral grade engine oil for multi-valve, modern engines. The high quality base oils and latest technology additive package offers greater protection at cold start and assists with reducing unwanted sludge and deposits. Suitable for all gasoline and diesel passenger vehicles with normally aspirated and turbocharged engines.
Specifications:
SAE 15W-40 API SL/CF

whats price different between motul and fuchs?

Last edited by Gaz on Sat Apr 29, 2006 4:33 pm, edited 1 time in total.

high km's doesn't always mean you have to start using thicker oil. my car has 292000 km's on the clock and i use shell helix ultra (5-40) and have done for about 8 years. i won't say it doesn't use oil but what it does use is well within tolerance. over 5000km it may use 2-300ml. not sure how accurate the oil pressure guages are on the dash but it always reads between 1/2 and 3/4 sometimes higher. i will always recommend a full synthetic over semi or mineral base.

it can be detrimental changing from mineral to synthetic as a lot of the carbon build up around the motor is also acting as a seal. synthetics will tend to clean all this out (to an extent) and could shorten the life of the motor. having said that i bought my car on 230000 and changed to shell helix ultra straight away and have never looked back. economy is pretty good in mine too. 10.8 city and 7.8 highway. i have no doubt the oil plays a small part

the motul 8100 is full syn oil and the cost represents that.
not sure on retail price (i'm not the salesman at work) but i think it's around $65 for 5L we also use fuchs oil at work and put simply i believe them to be tw best oils you could put in your engine

i'll always recomend you use the recomended oil for your engine unless there is a problem that there is no other cost effective solution for.

hm, not to keen on switching to a fully synth oil, mainly cause of how old it is. guessing that fuchs is semi synthetic, next oil change is due in 3500km, might try the fuchs stuff if the price is reasonable.

i got no real reason to run ticker oil i guess. got some lifter noise, but that was after a cam change so i think i just got a buggered HLA.

would it matter if wen i get my motor back to run penrite sin 15w 40???? it has forggied ACL pistons (heavy duty) , and new rings etc...

hopefully this stops talk of people running bloody 20W60 and who knows what else in there donks!

dont run the engine in with synthetic oil.

run it in with a 15w40 mineral oil