Oil, Oil Or Oil?

[Jimmy Jazz 0]

I want to do an oil change on my car for peace of mind and I was in Halfrauds the other day and noticed that their 5L oil is on BOGOF....

 

 

BUT,

 

is there stuff any good???

 

My car has 108k on the clock and IMO is a sweet engine and has been pretty well maintained. Should I use something more fancy or will this other stuff work just as well... I do some town driving so my car isn't just for ragging all the time

 

Also, which should i pick - e.g. 10w40 semi-synth???

 

 

Thanks for any help!!!

 

J

[boldy205 74]

normall 10/40 not sy nthetic or semi

[Jimmy Jazz 0]

normall 10/40 not sy nthetic or semi

 

 

so mineral???

[SPGTi 2]

normall 10/40 not sy nthetic or semi

 

Why ????? And please don't say that synthetic or semi are too thin as anything rated at 40w has the same viscosity spec when hot (can't remember the exact temp this is measured at).

 

Steve

[Beastie 1]

Why ????? And please don't say that synthetic or semi are too thin as anything rated at 40w has the same viscosity spec when hot (can't remember the exact temp this is measured at).

 

Steve

 

*puts on devil's advocate hat*

 

actually please don't say it's "too thin" because that means precisely nothing. Why can't he suggest that it's not viscous enough though? Synthetic oil has a very different viscosity rating when it's cold and don't forget that around 80% of engine wear takes place when the engine is cold.

 

*removes devil's advocate hat*

[SPGTi 2]

*puts on devil's advocate hat*

 

actually please don't say it's "too thin" because that means precisely nothing. Why can't he suggest that it's not viscous enough though? Synthetic oil has a very different viscosity rating when it's cold and don't forget that around 80% of engine wear takes place when the engine is cold.

 

*removes devil's advocate hat*

 

*puts Pumaracing hat on*

 

Think about the statement you have made, research what the ratings on oil mean. clue 1 : the viscosity reduces as it gets hotter.

 

*removes Pumaracing hat and throws it in the bin*

[Jimmy Jazz 0]

and so...

 

Should I use a fully synthetic oil? or a semi??

 

and, is the Halfords own brand oil any good??

 

James

[Anthony 1,000]

Just use normal 10W40 semi-synthetic - that's plenty good enough for a road and occasional track car.

[tom_m 0]

or even 15W40 as the owners handbook says

[Beastie 1]

*puts Pumaracing hat on*

 

Think about the statement you have made, research what the ratings on oil mean. clue 1 : the viscosity reduces as it gets hotter.

 

*removes Pumaracing hat and throws it in the bin*

 

LOL - I once tore into Dave for talking about oil in terms of "too thin". I don't think that you understand either my post or oil technology though. Maybe you do have some oil which reduces it's viscosity when it gets hotter. In which case I'm ignorant of it and I can't imagine what it's used for. What does it say on the tin? 40W/10 ?

 

edit: Oops - my mistake - of course I stock oils which reduce their viscosity with temperature: SAE 30 and SAE40 both do this. clue1: the oil might look thinner when it gets hotter but there's a reason that the big number follows the little number in the specification of a multigrade.

Edited July 26, 2007 by Beastie

[Rob_the_Sparky 9]

Acts like a 10W oil when cold and a 40W oil when hot. It is still thicker when cold but not a thick as a straight 40W oil would be.

 

Roughly correct?

[Edd-XS 0]

Now now kids! lol

I use 10/40 semi synth in mine, and I think the 'general' concenus is, that aslong as you keep an eye on oil levels and change regularly that it doesnt make too big a deal what you use, unless your racing obviously!

However! I get motul oil free from work now so im sorted lol

Hope this helps mate

Edd

[brianthemagical 1]

there are even a number of threads on this sit e that explain about oil. 10w/40, at a winter temperature, measured at -18 i believe, the oil acts like 10weight oil at -18 so it's still very thick but not as thick as 40wt oil at -18. the second is measured at 100 degrees i think and in this case acts like a 40wt oil at 100 so it's thicker than a 10wt oil at 100 but thinner than a 10wt oil at -18 and thinner than a 40wt oil at -18. it's not magic that the oil looks thinner when warn, it actually is.

 

i used halford stuff for a bit when chasing my oil presure probs and it seemed fine. i did have heavilly scored bearing when i took the crank out but i don't know when or how they came about so can't blame owt realy. 10/40 15/40 have worked fine for me but at my next change after the engines run in i will be changing to silkolene pro s 5w/40.

[WildCards 0]

Most fully synthetic oils are not proper fully synthetic oils, they're cracked which (if I remember correctly) basically means they are a semi with additives. I know Amsoil is a proper synth and that is all I use in any of my cars because I believe I can feel a difference, especially in older cars. Millers and Silkoline I think are the others, but everything else is tosh (again, if I remember correctly). My Mi will be run on Amsoil 20w50, unless I feel it needs a different weight.

Edited July 26, 2007 by WildCards

[Beastie 1]

Acts like a 10W oil when cold and a 40W oil when hot. It is still thicker when cold but not a thick as a straight 40W oil would be.

 

Roughly correct?

 

Sounds like a sensible way of looking at it to me, Rob. Viscosity is not just a measurement of "thickness" - it is in fact a measurement of how much a fluid deforms under shear stress. There are two basic ways of describing viscosity: Dynamic Viscosity or Kinematic Viscosity. When I was at college we were only really interested in Kinematic viscosity which is the method commonly used for measurement of lubricating oil. These days laboratories use units of Stokes although end products are expressed in old fashioned SAE units which consumers readily understand. When calculating degrees stokes temperature is a calculation factor so that magnitude of kinematic viscosity is temperature dependent. This is why the oil in your example can appear "thicker" when cold although the viscosity is lower. (you can tell why I so dislike the thick and thin terminology now....) I did warn everyone that my devil's advocate hat was in place I wasn't doing it just to be awkward though: Many people have very definite opinions of what their engine "must have" and yet few really have much understanding of oil technology. It's always worth questioning our prejudices and analysing what properties we are looking for and why. Incidentally I'm a firm believer in using the best quality as well as the most appropriate product you can - the saying in the trade years ago used to be "oil is cheaper than engines".

[SPGTi 2]

This is why the oil in your example can appear "thicker" when cold although the viscosity is lower. (you can tell why I so dislike the thick and thin terminology now....) I did warn everyone that my devil's advocate hat was in place

 

Please stop talking rubbish. I do not care how you measure viscosity, whether with a cup, brookfield, use centipoise, centistokes etc etc as an oil gets hotter its viscosity gets lower. Find any technical datasheet for an oil eg Amsoil synthetic 10W-40and you will see that at 40C the vis. = 90.5 cst and surprise surprise as it gets hotter the vis. = 14.9 cst which, unless I am mistaken is lower.

[SPGTi 2]

Jimmy Jazz

 

Sorry for going of topic slightly

 

Have a look at the pinned oil topic (I think in the XU modification section) and also this thread HERE .

 

It should help you make up your mind about the oil. I would have thought though a semi-synthetic 10w-40 that has all the correct approvals should be fine for a std road car.

 

Beastie

Maybe you should pull that "devils advocado (no not a spelling mistake) hat" from off your eyes and get aquainted with facts, reading those threads mentioned above should help.

[jackherer 543]

"devils advocado (no not a spelling mistake)

 

There is definitely a spelling mistake there :D

[SPGTi 2]

There is definitely a spelling mistake there :D

 

No I mean't advocado not advocate, as in being facetious.

 

Steve

[GLPoomobile 958]

No I mean't advocado not advocate, as in being facetious.

 

Steve

 

Avocado surely! Or is Advocado some sort of new, GM fruit?

[jackherer 543]

Avocado surely! Or is Advocado some sort of new, GM fruit?

 

A LOT of people seem to pronounce Avocado thus, and (with 55300 hits on google) apparently spell it that way too.

[GLPoomobile 958]

A lot of people say "brought" when they have purchased something. That really bugs me.

 

 

 

 

 

Sorry for the off topic, but this thread was getting well boring anyway

[Anthony 1,000]

A lot of people say "brought" when they have purchased something. That really bugs me.

Ut-oh - you're going to trigger off a rant by Pugnut if you're not careful

[jackherer 543]

No I mean't advocado not advocate, as in being facetious.

 

Steve

 

As we're on the subject that ^^ is also wrong.

[JayCC 0]

I just use the GM/Vauxhall 10w/40 stuff from my local motorfactors. Its like £10 for 5litres and does the job. Maybe i will take Oilmans advice and try some of the good oils, but its out of my price range at the moment.