Oil FAQs for your Classic

Penrite’s 20W/60 (top) is a special thicker oil for top oil pressure;

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Readying your classic for the hectic season ahead? Then you can’t just use any old engine oil if you want top performance and reliability over the coming months. Here’s why!

There seems to be a huge variety of engine oils on the shelves these days!

You’re not wrong. With over 100 different brands and blends on sale it’s easy to use the wrong one in your car and even experienced mechanics have been known to make such an honest mistake.

Why is this?

The days of universal oils are long gone and for many modern cars it is almost a dedicated part number, sospecialised are engines and their lubricants. Use the wrong oil on some new cars and you even invalidate the manufacturer’s warranty!

What does an oil do?

Engines may have changed radically over the past 100 years, but the role of its lubricant hasn’t. Oil provides that essential protective shield between the unit’s sliding surfaces, such as its crankshaft and connecting rods and the pistons/bores. Although they all look and feel silky smooth, under a microscope they are as jagged as the lunar surface. Without a film of oil an engine will seize up in seconds. But oil does much more! The lube must safely carry all the harmful fallouts produced during a typical combustion (firing) cycle such as corrosive acids, tarnish deposits, soot and coke to the oil filter where the lube is cleansed to do its job all over again. It’s a tough job and one that’s carried out under extremes of driving conditions, temperatures and engine revs - perhaps for up to 20,000 miles these days. Also an oil accounts for around a third of the cooling properties engines demand.

I never knew it was that involved!

No, and many motorists and even mechanics fail to fully appreciate what a lubricant has to do. Because if they did, then they’d give the subject a lot more thought before buying their lube. And it’s reckoned that perhaps one in every four cars run around with dangerously low oil levels too. Ignorance in this case simply isn’t bliss!

But I like a certain make of oil…

And you’re not alone. Admit it, engine oils are like drink: we’ve all got our favourite tipple! However the secret of a lube’s quality has nothing to do with its name - or price - but what’s printed on the packaging. Crack that code and you may well change your sup.

How come?

A pair of respected authorities control lubricant quality. The best-known is the American Petroleum Institute (API), which has been around for decades and classifies quality alphabetically. On a pack of oil you’ll see the letter S (for Spark) labelling for petrol engines and C (for Compression) on diesels. Currently “SL” is the highest API listing, but you’ll still find many cheaper alternatives branding SF approval; a standard that dates back to the late 1970s but some real cheap and cheerful 20W/50s have a CC rating harking back to the fab far out 60s! Essentially the higher up the alphabet rating, the better.

What does ACEA mean?

The other quality assessor is the tougher European standard entitled ACEA. This stands for Association des Constructeurs European d’Automobiles and it replaced the old CCMC (Committee of Common Market Constructors) body during the 1990s. ACEA ranks oil quality from A1/B1 to A/B 4 (A standing for petrol, B for diesel, incidentally) although the ranking isn’t in a special pecking order but rather what the lube is intended for.

What about approvals from carmakers?

Yes these are very good indicators too. Look out for listed approvals from leading manufacturers; it is reckoned that the Germans (BMW, VW, Audi, Mercedes and Porsche) are the fussiest and as a result their rubber stamps are highly valued.

I only look at an oil’s grading, really. Is this wrong?

An oil’s grading is as crucial as its actual quality, but many modern oils are unsuited to old classics and by using the latest high tech oil you can do more harm than good. Today’s power units are so There seems to be a huge variety of engine oils on the shelves these days!

You’re not wrong. With over 100 different brands and blends on sale it’s easy to use the wrong one in your car and even experienced mechanics have been known to make such an honest mistake.

Why is this?

The days of universal oils are long gone and for many modern cars it is almost a dedicated part number, sospecialised are engines and their lubricants. Use the wrong oil on some new cars and you even invalidate the manufacturer’s warranty!

What does an oil do?

Engines may have changed radically over the past 100 years, but the role of its lubricant hasn’t. Oil provides that essential protective shield between the unit’s sliding surfaces, such as its crankshaft and connecting rods and the pistons/bores. Although they all look and feel silky smooth, under a microscope they are as jagged as the lunar surface. Without a film of oil an engine will seize up in seconds. But oil does much more! The lube must safely carry all the harmful fallouts produced during a typical combustion (firing) cycle such as corrosive acids, tarnish deposits, soot and coke to the oil filter where the lube is cleansed to do its job all over again. It’s a tough job and one that’s carried out under extremes of driving conditions, temperatures and engine revs - perhaps for up to 20,000 miles these days. Also an oil accounts for around a third of the cooling properties engines demand.

I never knew it was that involved!

No, and many motorists and even mechanics fail to fully appreciate what a lubricant has to do. Because if they did, then they’d give the subject a lot more thought before buying their lube. And it’s reckoned that perhaps one in every four cars run around with dangerously low oil levels too. Ignorance in this case simply isn’t bliss!

But I like a certain make of oil…

And you’re not alone. Admit it, engine oils are like drink: we’ve all got our favourite tipple! However the secret of a lube’s quality has nothing to do with its name - or price - but what’s printed on the packaging. Crack that code and you may well change your sup.

How come?

A pair of respected authorities control lubricant quality. The best-known is the American Petroleum Institute (API), which has been around for decades and classifies quality alphabetically. On a pack of oil you’ll see the letter S (for Spark) labelling for petrol engines and C (for Compression) on diesels. Currently “SL” is the highest API listing, but you’ll still find many cheaper alternatives branding SF approval; a standard that dates back to the late 1970s but some real cheap and cheerful 20W/50s have a CC rating harking back to the fab far out 60s! Essentially the higher up the alphabet rating, the better.

What does ACEA mean?

The other quality assessor is the tougher European standard entitled ACEA. This stands for Association des Constructeurs European d’Automobiles and it replaced the old CCMC (Committee of Common Market Constructors) body during the 1990s. ACEA ranks oil quality from A1/B1 to A/B 4 (A standing for petrol, B for diesel, incidentally) although the ranking isn’t in a special pecking order but rather what the lube is intended for.

What about approvals from carmakers?

Yes these are very good indicators too. Look out for listed approvals from leading manufacturers; it is reckoned that the Germans (BMW, VW, Audi, Mercedes and Porsche) are the fussiest and as a result their rubber stamps are highly valued.

I only look at an oil’s grading, really. Is this wrong?

An oil’s grading is as crucial as its actual quality, but many modern oils are unsuited to old classics and by using the latest high tech oil you can do more harm than good. Today’s power units are so precision made that they require lubricants as thin as water for a proper flow; treacle-like 20W/50 would block the oil ways. In contrast, use a watery synthetic oil in an elderly engine design with its wider working tolerances (and perhaps natural wear) and you’ll suffer from poor oil pressure and excessive loss due to burning at the pistons.

How do I decipher the viscosity code?

To work effectively, oil must provide the best all round working compromise, offering fast flow when cold and enough stamina when hot under varying speed and load conditions. On an oil pack you’ll see a number such as 20W/50. The “W” stands for winter, so W20 is a viscosity rating describing how thick the oil is when cold while the other, larger, figure (in this case, 50) refers to the lube’s ‘body’ once it has thinned out at operating temperatures. Remember; as oil deteriorates in service it loses its viscosity and so these figures fluctuate, which is why regular oil changes are so beneficial.

How about straight grades?

On many older cars, such as pre-war, it’s wise to use a monograde over a multigrade (an oil with two working grades). SAE 30 is the most common although a thicker SAE 40 is recommended for summer use. Multigrade oils were designed to alleviate the bind of using summer and winter oils and a 20W/50 lube is an equivalent of a mono SAE 30. If you are in doubt, speak to a specialist or your car club for best advice on the correct oil to use

The thicker the better in an old smoker?

Don’t assume that the thicker the oil the beefier it is in service; it depends upon what engine it is being used in and some modern units are extremely oil sensitive. That said, a fuller-bodied oil in an aging, wearing unit can help control poor oil consumption, such as specialist classic 20W/60 blend, although most units in good order could cheerfully use a lighter 15W/40 safely, too.

Should I go for a synthetic oil?

Because they are man-made, synthetic oils offer advantages over a mineral oil, such as better protection, broader viscosity bands and longer service life. That said,unless you own a modern performance classic such as a Sierra Cosworth or something turbocharged, synthetics aren’t too critical. In fact, their lighter constituency can lead to excessive oil consumption and even leaks, via worn seals and gaskets. Some experts also reckon a synthetic’s “searching” characteristics disturbs sludge and debris lying in an old engine. If you wish to switch over to a synthetic, flush out the engine first.

Why should I use a classic engine oil?

There are considerable advantages in using a specialist lube because there is no benefit in using an oil that’s “too good” for your engine. It’s all down to the unit’s design. A dedicated ‘classic oil’ from the likes of Castrol, Duckhams, Halfords, Morris, Millers Oils and Penrite offers the best of both worlds: that is current standards in quality twinned with traditionally refined formulations for the eras these oils were intended for. Not cheap but great for classic cars and enthusiasts who want the best!

There’s plenty of 20W/50s around for a lot less!

Don’t fall into this trap! Sure, dedicated classic oils are premium priced and you can certainly purchase five-litres of 20W/50 for around a fiver still, but these cheapies won’t be anything like the quality your classic deserves (although may be okay for a budget oil burning oldie to be fair). If you want a quality oil on the cheap then seek out supermarket brands such as Tesco and Asda, which are good stuff.

What other classic oils are there around?

Apart from normal oils you can also choose special lubes for fast road or motorsport use (some which are even syntheticbased). Also you can specify brews to help run an engine in after a rebuild or if it is to lay idle for long periods. Running-in oils are generally of low quality lacking the traditional anti-wear agents to encourage a quick bedding down process. Conservation oils, such as Millers’ Classic Preservation Oil, contain a vapour that coats the internals and safeguards against storage damage.

Your comments about modern oils in classics – does this also apply to transmission oils and greases?

Generally yes. Like engine oils, transmission lubricants have evolved into lighter, freer flowing affairs, which may not suit your car. Again, classic transmission oils and greases are available.

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• h3>What Oil is Right for Your Classic

 

• Monogrades

 

• These are for vintage and veteran engines, especially those featuring roller bearing crankshafts. Some pre-1940 engines can’t use oils containing detergents so check first

20W/50 (20W/60)

 

• This is still a popular choice for classics although aim for SF level quality at least. Specialist oils that boast a fuller bodied “60” rating are worth using to retain oil pressure

10W/40 (Semi synthetic)

 

• The ideal candidate for modern fuel-injected, catalysed multi-valvers and hot GTis. A similar, cheaper top grade mineral is just as suitable for most cars produced in the ‘80s

15W/40

 

• Generally a semi-synthetic oil, this is the right stuff for mainstream engine designs. A huge choice is available; ignore the name and concentrate on the specs on the pack