Is there any issue of using fully synthetic oil in these engines? Seeing as the Acclaim doesn't leak any I'm happy to use it but want to double check first. Should mean less frequent oil changes?

And does anything have to be done to the engine first or is it ok pouring mineral out of the sump and them putting synthetic straight in - ie, can it be mixed?

I think that the oils will not have much of an effect on each other, after all, you can get semi synthetic oil. I am no expert, but the name suggests a mix of the two. Make sure that you get the oil well up to running temprature before you drain it out if you are concerned.

I chose to use the recycled stuff from morrisons or asda, and change it every 3k with the filter. I have done this for all my cars over the years and have found no significant wear to the engine componants.

see how it goes

Again no expert, but I'd agree that it should be ok.
Rather than the cheap oil I've always used in the past, Halfords do an oil for the older car, so spend a bit extra on our cars now.

Mazola corn oil  is wonderful stuff

h

I use Amsoil Fully Synthetic in my Vitesse and the results are excellent, expensive oil is always less expensive than any engine rebuild.

L

Quoted from hrgserv

Mazola corn oil  is wonderful stuff

h

Did you say you were experiencing problems?

for the sake of a few quid i would use some engine oil flush & give it a good clean out before switching to fully synthetic oil.
Dan

How about using semi-synthetic for a few oil changes and then switching to fully syntheitc? That way all the mineral oil is flushed out.

Before my trip down south I had to top up Becky II's engine oil and all I had was some semi-synthetic. 500 miles later she is none the worse for it. I even averaged just short of 43mpg on the way down.

seriously never had a problem with acclaim engines on basic mineral 10/40 0r 20/50 changed the oil every 5000 miles imo fully synthetic oil is an expense you dont need to go to

0ne of our cars did 187000 miles like this the engine was still running fine, just the tin worm got to it
we had the car from 48000 and prior to that it had main dealer servicing (or not!)

h

I have been thinking about all this. With our, well, lets be honest, old engines, how many have worn out through poor lubrication? not many I would guess. Most seem to suffer general lack of maintainance,  or mechanical failure, and thats usually down to poor replacement parts. Or over-enthusiastc driving
Whilst modern spec oils do have some minor advantages, I doubt the vast majority of people would gain anything if they do regular oil changes. Exceptions include people who thrash their cars without mercy on endurance events, or drive like hooligans (my spit used fully synthetic )
So the toledo may get a fill of synthetic before the RBRR, but otherwise runs old skool  mineral.

I've been looking it up and there's a theory that says the synthetic oils can clean the engine and pick up the sludge which the mineral oil has left behind. Which can make the seals leak and also do some nastiness if the crud starts moving where it shouldn't. We'll see... I normally change the oil every 3-4k miles. More than needed but I'm guessing it's been worth it. The old (current) Herald engine got thrashed, I'm sure some will agree. Yet the bearings in it were absolutely spotless.

Think I will be going semi-synthetic first (Castrol Magnatec), just to see what happens. Apparently some bottles which say fully aren't actually that. They've just been fiddle with enough to scrape through. And American and European oils of the same name can have different specs etc. No idea how true it all is.

It's a Honda so designed and  bulit to modern and close tolerance.  Honda's like 15-40 full and semi synthetics.

I know people who are less than enthusiastic about Magnatec, people working in the oil industry.

Synthetic oils are invariably thinner than conventrional mineral oils. An engine which has no leaks on mineral oil can become very wet as lower viscocity oils find their way out where the thicker ones couldn't. This is in addition to the detergent issue you've already raised, which isn't a theory, it's a fact.

Cheers,
Bill.

Quoted from Rarebits

Synthetic oils are invariably thinner than conventional mineral oils.

Hi Bill,
So a mineral oil rated at SAE 20W50 has the same viscosity as synthetic oil rated as say SAE 30W60?

I thought the SAE rating referred to the viscosity at two temperatures and did not matter what type of oil it was?

Iain.

P.S. never used additives in my oil and always use Fully synthetic. Filter changes as normal.

Quoted from Spitfire6

So a mineral oil rated at SAE 20W50 has the same viscosity as synthetic oil rated as say SAE 30W60?

No, I meant in terms of availability. If (for instance) you need 20w50, you are going to struggle to find that as a fully synthetic. A 0w30 is going to find it's way through gaps which a 20w50 couldn't...

Cheers,
Bill.