fully synth vs semi synth in our cars? discuss!

[fR33faller]

Okay after discussing fuel in another thread it got me thinking so I thought I'd kickstart a discussion (or probably blow open a can o worms) for this site :)

I'm just wondering on ppl's opinions on fully synth vs semi synth? Mainly in older cars - ie: skylines, supra's, silvias and cars that are turbo-charged or hi-spec NA motors. We treat these things like high strung ferrari's but they were built back at a time when oil quality and refinement was 15-20 years behind what we have available on the shelves now so it makes me wonder. Theres alot of snobbery - "fully synth is the only way" esp. in turbo-charged cars but I've seen no difference personally on cars in the past in terms of heat or pressure of the oil.

Anyhow all constructive thoughts n comments welcome :confused:

can... worms.. lets go lol!

[styler2002i]

personally i have only used fully synth, for no reason other then its sound more healthy for the engine, but i didnt accidently pick up some semi once and due to the fact that my engine was running quiet low on oil, i decided to use the semi.

what i got was a noticeable increase in engine volume over time. so im guessing this was due to the semi.

back in the days when imports were booming, my older brother used to import some high power skylines and the contact in japan always stated that fully synth oil is best to use on these high strung engines (the guy modded his skyline to 700bhp - so im guessing he know a thing or two about engines)

on a present note the m3 only ever gets fully and it sounds as healthy and fruity as the day i brought it 4 yrs ago.

[Rik]

Here's a question. If the car has been running on semi all those years, and then someone comes along and uses fully synth. Can that not dislodge aload of crap from the less decent oil and end just fucking the car? I think I read that somewhere on another forum, and say to just run fully if you have had a rebuild so no shit can float about and block pipes up etc.

We need to get Opie the oil guy on the forum haha he's the god of oil!

[fR33faller]

yeah totally agree but you also have to remember the guy runs a business so is gonna sell the best oil he can mate. not wanting to be-little his knowledge in any way as I've bought from him myself, but I think ppl over-worry this issue a bit. Its not like we have to pump water around the engine or keep the tyres warm on these cars F1-style lol! I use fully synth in mine as much as possible, but I ran semi in it once cos I couldn't get anything else at the time and I saw no difference in response, noise, volume or general driving. I dont imagine the semi will be as robust as the fully synth but for the 1k of miles I wanted to do on it - it was just peachy.

I dont think any lodged contaminants would cause any damage myself - if there's steel shavings flitting about your engine then something bigger is an issue lol! If you ran semi for a bit then put full in and you do dislodge some bits then they should burn up in the combustion really - in short surely nothing a good hoofing wont fix hence why we're told we should open our cars up from time to time and get the chambers nice n hot n clean the pipes so to speak!

[Mud]

Well my Evo was run in on Semi and then it was changed to fully synch oil.

I dont know why, but thats the Way Mitsi did it back then (could have changed now I guess)

Although they did accidently put semi in, on one service and I didnt notice any difference TBH.

But I tend towards sticking with fully synch, but is there any hard facts about the exact effect to the engine?

As for Opie, they just join forums and make a couple of posts and then thats it, they just advertise the company and barely post any constructive posts or join in the community.....

[Rik]

On the tgtt forum he had some really good info and went into a lot of detail about stuff, didn't mention any of his products, even though he offers them with discount etc. Not sure what he is like on other forums but he's posted over 180 posts on ours about oil lol

I think I might try some fully synth, but i've always used semi in the starbo

[philyerboots]

well suabru recommended 10w-40 semi synth on my other scoobie when prosport serviced it but i have opted for millers 10w-60 fully synth..... no reason other than only best for my baby :D

[phat///M3]

I only use Castrol TWS Motorsport 10w60 in the M3.

[M7ammed]

So which one does BMW use in there cars?

[phat///M3]

Depends on the car Adood, they use 10w60 TWS in all the M cars.