The Saturn Sky Red Line is my first car that requires a full synthetic oil. Since then, I’ve done a lot of research on oil… so this won’t be my last blog post on the subject.

Synthetic oil is an oil that is far more pure – it’s created, rather than refined… as such, it’s typically better than standard mineral oil. It has smaller particles that better glide across your engine parts. This allows it to handle more extreme operating conditions, such as performance uses or extreme temperatures.

That doesn’t always mean you need synthetic, read your car’s manual! Synthetic oil is great if you want your car to last a million miles. But, most people sell their cars after seven years (on average), so for getting to 150,000 miles… it may not be needed. Synthetic can help if your car has started to burn oil though, as it runs cooler.

The High Cost of Synthetic Oil Changes

General Motors dealerships typically charge between $29.99 and $39.99 for a full service oil change, tire rotation, and standard inspection. However, a full synthetic oil change costs – brace yourself – $89.99 to $99.99.

The thing that really shocked me was, this is quite tame compared to some other auto makers.

Now while GM has its own dexos oil requirements for its cars, that hardly justifies the price leap. It gets even more illogical with dealers that charge even more, for even more standard synthetic oil.

You can buy a gallon of full synthetic oil, at retail, for under $20. Most engines use around a gallon. But worse – dealers and other mechanics pay less for oil, as they buy in bulk.

So why charge more than double the price for a synthetic oil change? The only thing I can boil it down to is – because they can. Most synthetic vehicles are more premium, more expensive. As such, their owners tend to have more disposable income.

Interestingly, GM has done its part to try and reduce this. GM’s dexos oil certification for example benefits from recent improvements in standard/mineral oil, and allows select synthetic blends (which are only partially synthetic), to be used. They’ve even gone as far as to certify these newer synthetic blends for older GM cars, like my Sky Red Line, that previously required full synthetic.

What You Can Do

Simple – ask for a price break, or bring your own oil. Tell your mechanic or dealer that you noticed synthetic oil is far cheaper in stores, and that you want to bring your own oil. Ask them what oil they recommend.

Or, even better, pull out your own manual and check for yourself.

It might seem a bit corny, or unprofessional, to take your own oil to a mechanic… but you may be surprised to find out that’s actually quite common. Many enthusiasts have favorite blends of oil, that mechanic don’t stock, but don’t want to go through the hassle of an oil change themselves. Enthusiast favorites generally are less profitable than generic barrels of oil.

Plus, if you’re under warranty, it adds peace of mind. It doesn’t take long to find some horror story of someone who changed their own oil, and then got into a fight with an auto maker when their engine failed under warranty. In an effort to squirm out of an eight-thousand dollar repair bill – a manufacturer will want proof you did your own oil changes. Having a mechanic shop do it, and keeping the receipt, is the best defense to that claim.

My Favorite Oils

My personal favorite oils depend on application. On my Sky Red Line, I use Mobil 1 5w-30 until the extended warranty ends, then I plan to switch to Mobil 1 High Mileage (the latter not being either GM 4718M or dexos1 certified, probably due to high ZDDP content). On my Pontiac G6, I use Mobil Super High Mileage 5w-30 synthetic blend, as it’s GM 6094M certified. And, on my Nissan Maxima, I use Shell Rotella T6 5w-40 full synthetic.

My Maxima supports 5w-30 and 5w-40 oils officially… I suggest switching to 5w-40 as the mileage increases, it helps fill the gaps that form in the engine seals. Plus I switched to synthetic in the hopes that it would help the head gaskets lasting longer by not getting as hot. Fifth-gen Maximas are notorious for chronic head gasket failure, mine was on its second set before turning ten years old.

Rotella T6 is marketed primarily as diesel oil, but it has been reformulated to work on gasoline engines (a mixed fleet or all-fleet oil, as they’re known – for both gas and diesel cars). It’s API SM rated for pre-2011 gasoline vehicles. Post 2011 model year cars typically require API SN oil certification, but that’s a post for another day.