Personally, after reading TSC's recommendations I now blend my own oil from a secret proportion of fish oil, filtered puppy seal blubber and stolen Johnson's baby oil. The puppy seal blubber has a naturally high protein content which is thixotropic and also has excellent viscosity modifying properties. And the baby oil makes the engine bay smell sweet too. No but seriously, for a 1.8GTI just use 10W/40 semi-synth and keep on top of the changes. I always use oil flush when I do a change too, this is probably going to start another debate....
I would personally be using a 0W40, that way your oil is as thin as possible when cold and then thins out to the correct thickness at running temp!
10W 40 semi-synth is best for a MK2 GTi, even VW agree! Thinner (fully synth oils) are designed for more complex and newer engines. Thin oil is specifically used for cars with turbo's etc (among other things, but mainly high performance) as the oil ways are not as wide! However I would not advise running your 1.8T on 0W30 or 5W40 as the oil is so thin it tends to run past the turbo seals into the exhaust system, causing the turbo to run a bit dry! lol. Either way. Stick with 10W40 Semi and change it every 6K!
The rise of synthetic oils has as much to do with manufacturers wanting to extend service intervals, as the day-to-day performance of the oil. A modern car typically gets serviced by the main dealer, and many manufacturers have a "service included" type of scheme. Also long service intervals are a selling point. An older VW, owned and maintained by an enthusiast, is serviced much more regularly and so this advantage of the synth doesn't have so much value. So, a semi-synth changed frequently, performs better than a synth changed less frequently. A synth changed frequently is better still, but the gains are tiny compared to the extra cost incurred.
Its not the op temp thats the problem, its when cold that it causes problems with the seals, especially with 0W30 stuff!
doesn't sound right manufacturs specifically suggest lower vicosity "cold" figure oils for turbo engines: A) because they are often fully synthetic and don't have the same problems "coking up" in the oil galleys, that is not doing a cheeky line at a party, but when your mineral oil "burns" due to the extreme temperature in your turbo having just popped down the shops, spinning the wheels all the way and you turned the engine off with the turbo glowing red like your mums lava lamp. B) the lower viscocity reduces the period that the bearing has no oil pressure on start up. if its getting by your turbo oil seals at engine start up, you need a new turbo anyway
If he does do it, he does a bollox job - must be reusing old oil. What a sideline. Deliver the post and service your car.......... I actually saw the postie parked up in his van 2 houses up the other day, for well over an hour and a half - either he was just wasting time before he went back to the depot, or he was changing a cambelt or something.......
My postie could probably do it as a sideline, if he spoke English that is. He seems to do nothing else before 11am, after all!
I wonder if mine would cut the hedge, if I left him a wee note? He doesn't have much to do obviously, as he only bothers to deliver my post about twice a week. Nothing for days and then umpitty billion letters in one go.
im now due for a change, im going for the 5w-40 oil, im going to my usual shop to see whether they do a millers semi or fully synth in 5w-40 and whether there is a big difference in price. the other week i had to top up my 10w-40 oil, the can had been in the back of the car over night. as i added some to the tank it was thick cos the weather was really cold that morning, hence im going for 5w-40 over winter. how much do you lot pay for synta gold then? i recon millers will want about 26 for 5L of full synth... and about the same again will be needed for top ups (about a litre per 1000 miles) or i may find some cheap car lube stuff for top ups.
I've definately noticed a difference in running on my valver between using 20/50 and 10/40 oils. I've noticed that the hydraulic tappets tap like hell when the engine is cold using 20/50 and are nice and quiet when using 10/40. When hot no probs with either oils. I quite like Tesco's own brand 10/40w oil, you might try it if your engine's older like mine and you're building a replacement LOL it's under 5 for 5L!!!!
right. i brought some millers 5w-40. 30 for 5L. the semi synth 10w-40 is about 15 lol so i was wondering if this was the best idea as i need to keep top-up oil in the car! later that day i was in makro. they have car lube 5w-40 fully synth for 15 for 5L!! i brought 2 and will take the millers back. i doubt the millers is twice as good lol if anything ill keep the 5w-40 for winter use as it gets cold, the 5w may help there. my tappets have been tapping a bit too lately, but im running some ATF through there in readiness for my oil change on saturday. when i go to fully synth i expect another 20bhp to be unleashed, fo sho
oh... and with the saving i made between the car lube and millers... ill be able to afford the rocker cover gasket
