Probably the most basic automotive service is changing the oil and oil filter. In the engine, oil is held in a reservoir, usually the oil pan, and pumped through a filter and throughout the engine assembly to lubricate moving parts while the engine runs.
Over time, acids and soot from the combustion process, wear from bearings, moisture absorbed from the atmosphere, and degradation from heat cycling all conspire to reduce the effectiveness of the oil. The filter removes particulates as they are produced or introduced, but this also becomes less effective over time.
The Cost of an Oil Change
Probably the biggest part of the oil change market is occupied by dedicated oil brand chains. For the most part, they set very competitive prices. Independent shops, full-service shops, and even some dealerships tend to price accordingly.
The average cost of an oil change is about £20 to £80 for most cars and light trucks. A vehicle with conventional oil will usually be priced toward the low end of the scale, while a vehicle that uses synthetic oil or a vehicle-specific oil will be priced toward the high end of the scale.
A dealership that is not pricing to compete on oil changes may be higher but might also have advantages such as factory-trained technicians doing the work. This can be a factor or not, depending on the vehicle and the disposition of the customer.
For light trucks with diesel engines, they often have much higher oil capacities and a different price range, which is usually from about £60 to £145. The procedure and time required are about the same, but the larger volume of oil makes the basic cost higher.
There is also the choice of using either conventional or synthetic oil, though most light truck engines use conventional oil. The synthetic oil change price is definitely more expensive.
Oil Change Service
Performing an oil change is simple. The oil is drained from the pan, the oil filter is replaced, the drain plug is reinstalled, and new oil is installed to the correct level. Also, the drain plug and the oil filter must be torqued correctly, the oil used needs to be the correct viscosity for the engine and the correct specification.
Most engines will use basic, commonly available oil, but some use very specific types. If a specific type is needed, sometimes it’s best to schedule a service and make sure that the correct oil is available.
Another thing to be kept in mind is oil consumption. Even a new engine will burn a small amount of oil in normal operation, although usually not enough to cause issues before an oil change is due.
Older engines might or might not be so fortunate. The common recommendation is to check the oil level every 1000 miles or at least to check it periodically between oil changes to gain an idea of how much oil the engine is burning. Most manufacturers will say that burning less than one quart of oil every 1000 miles is acceptable.
This can be a problem when, for instance, an engine has a 4-quart oil reserve and a scheduled oil change interval of every 12,000 miles. The math does not work in an engine’s favour in this situation if the oil level isn’t checked regularly.
Synthetic Oil Versus Conventional Oil
The argument is a little complicated to make as all motor oil comes from the same place originally. All motor oils also have various additives to improve their performance and are all graded according to the same set of weight standards.
The primary difference is the level of refinement, which can come down to determining the exact size of the hydrocarbon chains in the oil itself. Synthetic oils are much more uniform in composition.
What this translates to in an engine is much more predictable behaviour over time. Synthetic oil keeps its properties longer and will tend to be a better lubricant for up to twice as long as conventional oil.
In principle and in practice, synthetic oil has some advantages. It’s also more expensive, though this is more or less offset by it being longer-lasting.
Most shops will stick with the oil that the vehicle manufacturer specifies. However, switching to a synthetic can be a good option if a vehicle is driven long distances frequently.
Conventional oil is as reliable a lubricant as synthetic oil if it is specified for an engine. This is as long as it is kept in mind that it needs to be changed sooner. Once the point where it should be changed passes, it degrades more rapidly.
“Sludging” is one of the main things that happens to conventional oil when it is past its useful life – a tendency that synthetic oil isn’t as prone to. That is where the oil becomes thickened and tends to coat engine surfaces thickly rather than draining back into the pan.
Sticking to surfaces, the oil can bake to a shellac-like coating, which can flake off and wind up in the oil pan. From there, it can get pulled back up into the oil pump, becoming a gritty abrasive that can clog passages and cause wear on lubricated surfaces.
How Often to Change the Oil
This is one of the more hotly debated topics. Among mechanics generally, the recommendation hasn’t changed in ages; it’s usually every 3000 miles for conventional oil and every 5000 miles for synthetic oil.
But there has been a long trend among manufacturers to extend the oil change intervals, even to as much as every 15,000 miles. Some of the reasons are that modern engines are better and cleaner, and modern oils (particularly synthetic oil) are better products.
Another less compelling reason is that one purchasing factor that vehicles are rated on is “cost of ownership,” which includes the oil change cost at scheduled intervals. A longer interval leads to a better number there.
Some oil manufacturers claim that their oil is good for 25,000 miles. This may be true, but likely only in ideal circumstances, and it’s difficult for a driver to know how ideal his circumstances are.
As a result of stretching out oil change intervals past the useful life of the oil and early engine wear, the prudent choice will be to err on the safe side. Where that lies is still debatable, and a number of factors are involved.
To help reduce guesswork, some newer vehicles have “smart” oil monitors that look at a number of driving and environmental factors and determine the time for an oil change accordingly.
It is also possible to have the oil analysed for the various factors that determine how well it is holding up and infer from that, ideally, how often it needs to be changed. This isn’t really cost-effective for most car owners. However, many fleet owners do that, and generally, the results are that factory-recommended intervals are okay and can even be extended longer in some cases.
Again, it helps in that case that fleet vehicles are typically newer and driven in specific kinds of circumstances and known environments. A fleet owner can also weigh the advantages of consistent large savings on maintenance against occasional failures.
But it often comes down to costs versus risk. Neglected maintenance is a primary factor in early engine failure, while oil changes are cheap, whereas an engine in a newer vehicle can cost more than £12,000 to replace.
Mechanics tend toward the conservative side as seeing engine failures is a daily part of their job. The main concern of a vehicle manufacturer may be failure costs during the warranty period, which is only a relatively short (and clean-running) period of an engine’s projected useful life.
Most individual vehicle owners tend to split the difference, more or less, which is fairly sensible.
What to Expect With an Oil Change?
It is somewhat common knowledge, but there is often very little profit in changing oil. The prices are usually not far above the cost of materials. How an oil-change business continues to operate, then, is to sell other things as well, which is commonly referred to as “up-selling”.
Most often, the focus is on the easy jobs that can be quickly done on a lube rack, such as air and cabin filters, fluid changes, and other things on a maintenance schedule that might be due. It’s a normal thing to have records perused, and anything that might be overdue is recommended at that time.
Most shops will also do a brief safety inspection, checking for leaks, looking at the condition of the brakes and tyres. Usually, headlights, brake lights, turn signals, and running lights are checked and recommended if necessary.
Most places that do oil changes will also do tyre rotations, and that is a common, inexpensive service that is often done on the same schedule as the oil change.
Whether or not to have additional work done while the oil is being changed is a matter of weighing the cost versus the convenience. Having some idea about how easy basic vehicle maintenance is helps with decisions.
There are a number of simple things that an average person can do to their own vehicle; replacing the air filter, for instance. And then, a look at what labour charge the shop is asking for that versus how easily it can be done.
For fluid changes and flushes, the best approach is to be familiar with the scheduled maintenance in the owner’s manual. It’s common for shops to recommend services on a generic schedule, while the vehicle’s schedule might use a much longer interval or not require them at all.