The compositions of oils for modern vehicles are very different from those required for older vehicles. Modern engine oils meet the latest SN/CF API classifications and ACEA and OEM specifications related to fuel efficiency, drain intervals and exhaust emission systems. They are specifically designed for the needs of modern engines.
However, a classic car engine can have the opposite characteristics. Cork / graphite / tow seals, low pressure gear driven oil pumps, larger oil passages and more reliance on “splash” and “stick” lubrication, lower revs and larger clearances between parts. Such a different engine design calls for a totally different lubricant and the Castrol Classic Oils range offers formulations for older vehicles that have been specially compounded for the job they need to do.
DIFFERENCES BETWEEN THE COMPOSITIONS OF CLASSIC AND MODERN ENGINE OILS
DETERGENTS: An unsuitable detergent in the oil composition can cause rubbers and lacquers to adhere to the hottest components of the engine and block the oil passages. Also, too much detergent can cause metal ash to build up in combustion chambers and piston crowns.
In classic vehicle engines, With traditionally high oil consumption, this can lead to knocking and cranking. In older engines, where carbon has accumulated over several years, detergents in modern oils can have a "washing" effect, causing the carbon to loosen and block oil passages and spray jets. High levels of detergent can also “wash” carbon residue from seals and gaskets, causing oil leaks where the carbon itself is creating a seal.
ANTIOXIDANT: Insufficient antioxidant causes oil to thicken rapidly during high temperature driving, resulting in the formation of large amounts of carbon, rubber and varnish that clog oil passages, filters and piston rings.
ANTI-WEAR ADDITIVES: They are added to ensure that if the oil film between moving parts breaks prematurely, these additives prevent metal-to-metal contact causing irreparable engine damage.
CORROSION INHIBITORS: Internal engine parts can be pitted by corrosion, rust from acids, and water vapor that form during combustion. With the right corrosion inhibitors, engine components are well protected.
DISPERSANT ADDITIVES: Special dispersant additives prevent soot, wear metals and combustion by-products from settling on the crankcase and other areas of the engine, forming a thick sludge that can block filters and oil passages.
DEPRESSOR ADDITIVE: If there is an inappropriate pour point depressant additive, the oil stops flowing at low temperatures, causing excessive stress to the oil pump or, in certain cases, a lack of oil at startup, causing a complete system failure lubrication.
The Castrol Classic Oils are specially formulated In the style of the original products, but using the most suitable and carefully balanced additive technology to provide the best protection and performance for your classic engine.