Mk3 Cavalier Owners Club | Vauxhall Cavalier Dot Com

I was told [by Opie] that for ultimate protection there's nothing to beat an esther based oil - as frequently used by the racing people. But these are very pricey even on eBay. Has anyone come across a 5w-40 esther that is affordable, or am I wasting my time looking?

There are plus points to using ester based synthetic oils,
Such as lubricity and high volatility-temperature thresholds.
There is also an inherent polarity of charge, which causes the lubricant to adhere to the metal with a film like layer.

Ester based lubricants - formed by the mixture / reaction of an acid and alcohol, have been used in various roles of lubrication for well over 60 years.

In answer to your question - yes a synthetic ester based oil can be very good for your engine -
BUT!!

I have always found GM / Vauxhall / Opel home branded oils and lubricants to be the best for your Cavalier.
They are also not as expensive as you might think.

On the whole a Cavalier engine is very durable (most are quite bomb proof).
The important thing is to use a good grade of oil, and to service the vehicle regularly.

I am always a little sceptical when a salesman is telling you what to buy.
After all - he is trying to support his family and pay the mortgage.

Being in sales myself I can see the logic of treating all salespeople with a well-oiled bargepole.

It may be that an esther oil however desirable is a bit OTT for my engine in spite of all the TLC. However the man who rebuilt mine advocated a 5w-40 oil and he is the boss. As I understand it, please put me right if I'm wrong, GM don't do a 5w-40 fully synthetic? If not then I'm looking around for an alternative.

A final word on ester based lubricants -
They would be more useful if you planned to give your engine a hard life,
Such as giving it a good thrashing down a quarter mile drag strip on a regular basis.

GM do 5w30 and 10w40.

The recommended grade for mk3 Cavs is 10w40.

I let it off the leash every so often but 1/4 mile drag strips are not my scene - though I would rather like to visit one sometime (even if only as a spectator)! The problem is that the car will stand outside for 1 - 3 weeks at a time and the more the oil can stick to the surfaces between outings the better for the wear.

If the man specifically recommends a 5W-40 then that's what I'll try for. I have used 10w-40 up to now.

It is a shame that oilman has not offered one word of evidence or advice in relation to your query.

Hmm - I would like written documentation before I go to the extra expense of buying a specialised ester based oil.
Especially when the manufacturer's recommended 10w40 oil has worked perfectly fine for my vehicles which have covered half a million miles between them.

Call me cynical, call me critical or simply accept that I work in a world that requires evidence based decisions.

Not to contradict anything that has been said on here by oilman or anyone else, but I'm pretty sure that you (Telegram Sam) have asked the 'what's the best oil' question a number of times before, and the response has always been the same: GM's own 10/40 is excellent quality and value. In fact, most GM lubricants are of excellent quality.

I'm not doubting that at all but if the man who rebuilt my engine and is responsible for it recommends a 5w-40 and as far as I can tell GM don't do a 5w-40 then I have to look around for an alternative. [I've still got some GM 10w-40 in the garage- unused!]

Stick with GM's OILS.

Thinking logically -

If Mr GM / Vauxhall / Opel felt that the best stuff for his engines was a 5w40 brew,
then I am sure he would have put it within his product range.

Makes simple sense to do so, if he wants his engine range to be well looked after and
for them to last as long as possible.

We cannot compare the recommendations of the boss of an engine building company to the research and development department of a multi-billion dollar car designer and manufacturer.

Maybe you are looking too deeply into the subject matter...

You know the feeling being out of your depth between a rock and a hard place?
What's been in since the engine rebuild is 5w-40, I can't change that (other than do another oil change!). All I can do is decide on what to top up with between now and next year (low mileage).
Fact is that there are 5w-40's on the market. Why GM don't include one in their range is way beyond me technically bearing in mind that they bolt cars together rather than dig holes in the ground under the North Sea themselves.

Most cars use 10w40 or 5w30 nowadays, Only a few odd ball cars that have 5w40 and most of them could use the 5w30 oil really.

Your best changing to gm 10w40 on your next change and stick with that oil.

Telegram Sam wrote: bearing in mind that they bolt cars together rather than dig holes in the ground under the North Sea themselves.

Not wanting to sound confrontational, but -
I am sure neither Opie nor your engine builder dig holes in the ground under the North Sea any more than Vauxhall R & D does.
(Just trying to understand the point of your last statement).

Looking at the Opie site, it is more or less a motor factors with lubricants as it's main sales line.

It was perhaps a bit confusing apart from saying that I am faced with conflicting points of view: GM as a car manufacturer's brand vs. Shell & co on the one hand, and the various different grades recommended on the other.

Branding apart, my very limited understanding of the science is that a 5w-40 has a greater "latitude" (correct terminology?) than a 10w-40.

I was under the impression that Opie had rather more status in the lubricants world than the average motor factor.

Use Miller's 5-40 nanodrive.
Its proven anti friction oil. Less friction, less noise, less wear Better engine performance

Interesting! Though this is back to the non-GM ("triple") ester tack that I started out from. I might be tempted to take 1 L for top-ups which should keep me going for quite a bit.

You shouldn't mix oil types.
For a normal motor gm 10-40w is fine

What I've got now is 5w-40 synthetic. Or do you mean not to mix non-ester with ester?

Yes exactly different oil specs

Telegram Sam wrote:What I've got now is 5w-40 synthetic. Or do you mean not to mix non-ester with ester?

Latest twist on this is that whilst 5w-40 is preferable to 10w-40 apparently for a hi-lift cam engine, ester racing oils are often (always?) "low" on detergents due to being changed frequently, and this makes them unsuitable for longer life road use. I don't know if there are any exceptions but I read somewhere something from Gulf specifically warning against use of theirs for road rather than track use. Nothing is simple.

Honestly, I really don't see why 10w40 won't do - unless someone can give me specific information as to why it shouldn't be used, then I recommend that you use that.
Hell, it has done the engine proud so far.

Why the drama. If you wanna be cheap use 10/40 or expensive use the ester oil.
End of story really

Interesting to see that Tesco, Morrisons, Wilkinsons .. are now including 5w-40's in their own brand range. Each comes with its individual collection of API, ACEA etc specs. I was comparing these with the locked Oilman's "bible" thread which is now almost 5 years old, trying to work out if the own brands were as good as the more expensive proprietary brands. Gave up in the end.

No drama here...

I just live by the rule - "if it ain't broke, don't fix it".