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MG MGB Technical - Engine oil.

I would like to know if Halfords 20/50 engine oil is ok to use in my 1967 MGB, I only do around 1500 miles a year. What amount of ZDDP in Halfords compare with Castrol, as the amount of zinc has been reduced in oils generally. Also as I only do around 1500 miles a year is there a need to change the oil every year,could I change every other year.
Thanks for any replies.

a few people on here you will find dont like halfords oil because can not sealed and say anything could be put in it. having said that i have used in my 70 bgt and 75 midget and find it better and easier to get than any other iv used.i find my oil pressure on both cars very slightly higher and consistent than when i used other 20/50 oils. i only do about 1500 miles a year but still change.

Your question was answered recently on the forum in detail. Much of it was above my head. but Halfords oil was not very popular.
An oil that was recommended to me was a Classic 20/50 oil by Comma. I found it online at a reasonable price of around £17 a gallon. and by buying 3 gallons it came post free. (some for me and some for a friend)
Trevor Harvey

No matter what your annual mileage, leaving the oil in the sump for more than a year can lead to expensive problems. Acids build up in the oil as well as moisture and they can wreak havoc on your crankshaft and connecting rod bearings. Changing your oil and filter, at least once a year, is cheap insurance against major breakdowns down the line. RAY
rjm RAY

On thing I do not understand about Comma“s Classic 20w50 oil is that its content of Zinc, Calcium and Phosphorous is much lower than in the 20w50 Comma Sonic oil that I have used for the last five years or so. I thought it should be the other way round?


Halfords is made by Comma so maybe no difference there, except perhaps the sealing issue, although the can looks exactly the same bar the printing. I've started buying Unipart as it's formulated for 'older' engines so should have more ZDDP. Unfortunately it's almost impossible to find out how much ZDDP any oil contains. GTX has about half now than it used to. You might like to have a look at this - - but don't expect much by way of hard and fast conclusions!

Sonic is new to me, and going by their technical data sheet it contains more than anything else I've come across, in most cases typically double, including their Classic.
PaulH Solihull

I've always been a fan of Morris Oils of Shrewsbury. I use their Classic 20w/50 in both my 1800 and V8. Ring them up their Tech dept is always happy to talk.
Allan Reeling

Barney Gaylord--the MGA guru--believes that the only time you may need extra ZDDP is when the engine is first fired up to break in a new cam (if I understand his position correctly). He uses regular 20W50 and puts on hundreds of thousands of miles with no problems, with no particular concern for ZDDP levels.
JM Morris

What Barney (and Crane Cams) says
Geoff Ev

We stock zddp additive made by Chemodex to enhance the oils available. We use 20/50 semi-synthetic(not cheap but difficult to obtain) oil and enrich it with the additive.

Peter Burgess Tuning

Peter, I would value your recommendation for what lubrication to use when I run in my reconned engine (rebored to 60 thou, reconditioned crank with new bearings and new camshaft...also one of your fast road heads). I'm getting a bit paranoid what with all this talk about ZDDP levels.
Steve Church

Hi Steve

I prefer straight 30w mineral oil as it contains no additives and lets the engine bed in. We use moly disulhide paste on the cam and followers and this stays on for the initial bed in.

You should be able to get the oil from GSF as it was the spec oil for VW air cooled engines.

Peter Burgess Tuning

I found Comma Premium on Amazon £10.98 post free. It's the same API as Classic.
c cummins

Sonic is better than Classic for its extra ZDDP.
PaulH Solihull

This thread was discussed between 08/01/2012 and 30/01/2012

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