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[Solved] 2008 Pontiac G5 - Oil type change?


Topic starter

Greetings from Canada,

I drive a 2008 Pontiac G5. Approaching 300,000km. Original engine and transmission. Mainly highway mileage.
No major issues. I have always used conventional oil.

Would it make sense to change to synthetic oil? Or would it even make a difference so close to the end of the vehicle lifespan? 


3 Answers

Use what is recommended in the maintenance section of your owner's manual.


If you bought the vehicle brand new and know the maintenance history, then you might be able to do the swap. If not, you're gambling. I made the swap in my '99 Ranger I bought a few years ago. After the first couple oil changes, I noticed it only went through around a quart or so every 5k miles at 260k miles. I made the swap and it hasn't changed oil consumption over 20,000 miles later (4 or 5 oil changes later). 


I'd keep using what you're using. Synthetics are thinner viscosity and you may end up with a few leaks. If it ain't broke don't fix it.

5w30 is 5w30 viscosity, synthetic or not

Synthetics tend to have more detergents in them than conventional petroleum based oils. That's why doing the swap can cause leaks on a worn engine. Old engines oftentimes have crud buildup that blocks oil leaks. The extra detergents in synthetic are meant for maintaining modern, tighter built cars and can pull the "beneficial" crud out and expose the leak.

Bad wording on my part.