Which oil?

[Space1999]

There's no reason you will get leaking gaskets from full synthetic. It's the grade of oil (i.e 5W30) that will cause leaking gaskets, not the fact that it is synthetic or not.

Always use synthetic if you can, it gives better MPG and power, because the friction is lower, and of course it protects your engine better because it doesn't 'crack' (i.e. break down into carbon) under load.

The best of the best is ester synthetic, such as Redline or Gulf competition - Opie sells it all.

[BMCC]

Just ordered 5L of 5W-40 Shell Helix Ultra and a hamp shortie filter : £38 delivered from Opie Oils (25% discount)

As for plugs use the NGK platinum £40 odd quid for 4. Will last for 5/6 yrs

[prelude_h22]

Some say if your mileage is high then use 10w/40 and if its low mileage then use 5w/40

my engine has done 60k - so its still pretty young. Hence i am using 5w/40

have been using various oils in the past. Pretty much anything which is on offer at the time of service

Silkolene pro S, Eneos, Motul, and shell

Just ordered 5w/40 motul x-cess from jap service parts for my next service

[wurlycorner]

There's no reason you will get leaking gaskets from full synthetic. It's the grade of oil (i.e 5W30) that will cause leaking gaskets, not the fact that it is synthetic or not.

I've had old engines start leaking oil when I switched them to fully synthetic (same grade).

[Space1999]

That's most likely to be down to the fact that you flushed out dirty old oil full of crud (which was stopping the egress of oil through the seals), rather than the fact that the new stuff was synthetic...

Either that, or that particular synthetic had a good detergent package which started cleaning out all the caked-on carbon; again that's not specifically because it's synth.

[wurlycorner]

Yep, absolutely agree with the reasons above as to why it started leaing, but I find that synthetics just are much better at cleaning - they're more 'aggressive' in that way, hence they do tend to start leaks.

That's just my experience with them in various old cars over the years.

If I rebuild an engine or stick a new one in (ok I haven't ever had the money to do the latter but my dad did once!) then I definitely run fully synth, but if I pick up an old car then I just stick to semi now.

[sarah_h]

Well after an evening spent struggling underneath the car to get the sump bolt out my car is now full of new oil. Had great difficulty getting the bolt to loosen but a spanner and hammer arrangement came good eventually. I went with Shell Helix HX7 10W40 in the end. We'll see how it goes leak wise..

During one of my breaks from battling with the bolt under the car I fitted my NGK £40 spark plugs too just the fuel filter to have another go at now once I can get a filter that actually fits that is!!

[Space1999]

If you've got a brand new or newly rebuilt engine, it's best to use mineral oil for the first few thousand miles or so, to let everything bed in. Engines don't run-in well on full synth because the oil won't let the engines loosen up properly, and they can feel a bit 'tight'. After that though, go for full syn for extended wear protection and low sludge.

I used to work in viscometrics (oil design and testing) for a certain global multinational oil company, so have experience in this field. We used to run banks of VW Golf GTi engines on benches under load for mega mileages with different oil blends/brands, and measure the results...

We found ester full synthetic was the best, followed by standard 'full' synthetic, with semi-syn and standard mineral oil a very long way behind in terms of wear protection, MPG, flow rate, shear temp, etc. Semi-syn isn't worth bothering with; just get cheapo oil and change it twice as often, or get full syn and run for longer.

One thing I can say for sure is that if you don't change your oil at the recommended intervals, you'll destroy your engine! If you want to keep it tip-top use the best oil you can and change it at half the recommended interval.

[BMCC]

Well after an evening spent struggling underneath the car to get the sump bolt out my car is now full of new oil. Had great difficulty getting the bolt to loosen but a spanner and hammer arrangement came good eventually

A breaker bar would help. Really impressed your doing this!

[nitin_s1]

I have been using 10w-40 Semi synthetic in the Type-S..