Definitely. The word ‘synthetic’ isn’t a blanket term but all oils with the word synthetic on the label can be too easily dismissed by classic car owners. With that said though, special care and attention should be taken to make sure that, if you do decide to use synthetic oils, you’re using the correct one.Fully synthetic oils are perhaps the easiest to describe. They are oils which have polymers entirely synthesised in a laboratory and do not contain any petroleum out of the ground. This means the oil behaves far more predictably, and as a result is better suited to extreme temperatures. In extreme heat, fully synthetic oils have a more robust film strength, offering better lubrication – and flow better in colder conditions. The fact that they are man made does mean that, for now, these oils remain between 2 and 4 times the cost of mineral oils. Annoyingly there is no industry standard to what Semi-synthetic should mean. Some semi-synthetics are what you’d expect and have half synthesised and half mineral polymers, while others are entirely made of mineral oils and have been refined enough and had enough additives mixed in, that they’re allowed to call themselves semi synthetic. Oils up to Group 3base oils, given the viscosity and the chemistry, are acceptable to use in historic vehicles. The important thing to watch out for if you are considering a switch to synthetic is rubber hoses. Typically these start to weep or perish if the top range additive packages found in competition synthetic oils are run through them.