gingeRS

whats the difference between the two, i understand the fundamentals, but i'm wondering why it is always encouraged to spend more on fully synthetic as opposed to semi synthetic when they are both produced to the same spec

i did an oil change, used the correct grade of oil but only noticed afterwards that the oil i had bought was semi synthetic and now i'm a little concerned.....should i change it again

cheers

tabetha

As I understand it semi is a waste of time as the semi properties are soon lost due to base stock being mineral.
I would have a word with OILMAN, from opie oils 01209 215164.
tabetha

AlexF

I would look on here:

http://en.wikipedia.org/wiki/Synthetic_oil

Semi is not a waste of time at all.

gingeRS

good read that.....so the main reason for semi synth is to simulate a fully synth without incurring the costs of 100% fully synthetic oil

i now understand why some synthetics cost up to 4x as much as the same semi synth oils

COMEDY DAN

Very silly statement matey.

tabetha

Read what is written a synthetic is 100% synthetic and as such much better than semi synthetic.
Certain semi's are only 5% synthetic yet cost a lot more than a decent mineral, yet don't offer much at all in the way of extra protection.
A fully synthetic even at twice the mileage will still outperform a NEW semi, so it is more cost effective to use a FULLY synthetic, extend the mileage, and you still have better protection for the same price as two semi's.
So in THIS context not silly at all, semi's are a waste of money.
tabetha

Ginge !

mate talk to ANYONE who makes money selling anything and hes GONNA sell you what he wants !!!

semi's are fine, most oils are VERY VERY well refined these days and for road cars fully synth is a waste of time IMO due to the costs involved

infact look at the history of oil in general and how the companys where started you might even understand the confusion too

most mail dealers fill cars up with semi as the pump is there where as the fully requires going to the 205 barrels,,,,, i aint kidding either as when i first found out i was worried till i noticed no warranty claims for engines

i use semi in my scooby as i change the oil every 1000 miles, cost price of fully aint that pricey either just i know most fullys aint true fully anyway just got addetives to help it prolong life

iansoutham

One thing you need to remember with semi-synthetics is that the "semi" is a very vague word (as Tabetha metioned in part actually).

Different companies use different ratios.

An example: Comma semi-synethetic is only 24% synthetic. Millers semi-synthetic however is 57%. And only £3 difference in price round my way.

richm

there is a lot to be learnt from reading every article on this page:

http://www.opieoils.co.uk/technicalinfo.aspx

Ginge !

ich alot of it is interesting,,,, yet NOT ALL OF IT IS APPLICABLE TO MOST PEOPLE !

mopst oils these days are ALOT better than they was back in the 80's

foreigneRS

that seems a bit unnecessary, shit oil or not

Ginge !

mate i dont do much milage and it costs me 7 quid including the filter, ive changed it when i bought it, before the ring and after the ring and will change it again the next time i intend to drive it hard for long periods,,,,, the oils fine tbh just i hate black oil on a dipstick and it gets like thatafter a few weeks

remember when i do use it it gets some stick and prevetion is better than the cure

i also changed my fluid 3 times since ive had it too,, even though i had NO brake fade at the ring and the last time it was clear when i changed it

foreigneRS

too often is better than not often enough i suppose

Ginge !

there will be a time when its not often enough too im sure

just paranoid about the impreza,,,,, gonna do the transmission fluid monday too

if its cheep enough ill do it,,, considering i cant get the replacement engines through work i may aswell get the prevetion measures !

AlexF

On a scooby I would only EVER run decent full synthetic oil...

The crank bearings are tiny! No room for wear!

Ginge !

alex the actual SPEC of oil on a scoobie is semi synth !