Oil Change, Semi synthetic vs Fully Synthetic

[Timpy]

So I bought my 1.8t agu in July with 145k on the clock it now has 152k and has been 100% reliable apart from the odd electrical issues (interior lights only working part time and the rear windows having a complete mind of their own) I decided it was time to give her some fresh oil,I've been topping her up with halfords own brand 5w40 fully synth,I decided to use a good branded semi for the change (mobil 1 10w40) figuring it would probably be just as good as the halfords fully synth,how wrong I was after doing the oil change at the weekend I've noticed a significant loss in power,maybe as much as 5bhp,she used to pull nicely from about 1500rpm and there would be like a second kick 3000rpm when the turbo really came on now this has gone:-(now I read abit more into afterwards and it seems a lot of people opinions are split on this with guys saying 'i won't buy fully synth bcos they charge you extra for an oil that has no benifits over cheaper oils' well to me this simply isn't true,so after the new year I will be draining this oil back out and filling it back up with some proper fully synth,Millers looks to be one of the best oils out there and for £40 for 5l its not a bad price,the reason I write this post is bcos I was shocked at the difference oil can make to the performance of a car,if anybody else has anything to add on her that would be great ie similar experiences or oil recommendations,cheers

[james2]

Always use fully synth , i did use 10w 40 castrol magnitec when i first got the car then joined this site to find out it was not good and the blue anti freeze should be the red kind so change them both. I like the 0w 40 castrol edge oil .

[MoshiMoshi]

Anything other than fully-synthetic has been known to sludge up and block oilways and specifically the pickup pipe in the sump that feeds the engine top end and turbo. This can occur without warning and will ruin the engine.

However the nwrong oil is unlikely to cause those running issues. I'd advise having the car scanned for faults if you know somebody with a code reader/have your own. If not, let us know and we can recommend some.

Good luck!

[Wayne]

With those miles I would look to drop the sump and replace the oil pump pick up pipe the switch to 5/40 fully synth.

[paultownsend]

I just can't fathom why all 1.8t owners dont
go to Vw/TPS and use quantum platinum oil. It's always on sale and can pick up a filter too.

It's the exact spec/grade that our engines are meant to use. Deviating from this will lead to sludge build up.

It's so cheap you can justify a change every 5k.

[wessexgti]

I just can't fathom why all 1.8t owners dont
go to Vw/TPS and use quantum platinum oil. It's always on sale and can pick up a filter too.

It's the exact spec/grade that our engines are meant to use. Deviating from this will lead to sludge build up.

It's so cheap you can justify a change every 5k.

as above.

my AGU has been run on proper VW f/s oil for nearly all of her 206k miles and she drives superbly,the tester at my last MOT couldnt believe how low the emissions where from such a high milage car.and im still on the original turbo. when i changed the pick up pipe,the old one was fine but had it changed  anyway. using crap oil is a false economy. 

[mar_k]

I read a huge thread on one of the vag forums which gave reasons for not using quantum in 1.8t's

Something to do with the 501. something rating of the oil not being good enough to use in 1.8t's.


Trying to find the thread now.



I still use it in my LCR as 9 times out of ten its cheaper.

[paultownsend]

Mar_k if you could find it it would be a good read.
I'm sure the Quantum stuff is made by Fuchs or Silkoline. Used to be licensed to Castrol.

All I know is my pick up pipe is clean as a whistle. Matches my sump! And my engine uses no oil @ 110k.

[Timpy]

Always use fully synth , i did use 10w 40 castrol magnitec when i first got the car then joined this site to find out it was not good and the blue anti freeze should be the red kind so change them both. I like the 0w 40 castrol edge oil .

do u notice any difference in performance with these two different oils and why should you not use 10w 40?I'm glad everybody on here seems to agree on this though,fully synthetic is definately the way to go especially with the higher mileage cars,I can't understand people that won't buy it because it too expensive,my car used around about 1 and a half litres of oil in the 7,000 miles I've  done in it,which cost me around £12 so the don't exactly drink the stuff.

[paultownsend]

The 10/40 Just won't protect as well from cold