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2018 Subaru Forester - Synthetic Oil for 5500-6000 oil changes?

I have a new 2018 Subaru Forester with 9000 miles. The dealer recommends synthetic oil changes every 5500-6000 miles. I thought synthetic oil is for high mileage cars and supposedly extends life between oil changes. Is this kosher, or should I return my regular mechanic ?? What advice do you have?

First look in your manual at the service schedule . Second their is no penalty for changing oil sooner than the recommended time. Also why take a chance on voiding your warranty because you did not change the oil and follow the service schedule.


Incorrect. Many new cars specify synthetic from mile 1.

That is does BUT, @VOLVO_V70 is correct, do NOT extend the interval beyond what Subaru puts in the manual during the warranty period.

Full disclosure; I only use synthetic oil and have for over 30 years in everything including my lawnmower. An engine replacement can run $4000. Over 200K miles, the 33 oil changes might cost you an additional $30 each for synthetic totaling $1000 over that time. $1 spent to save $4? I’ll take that any day.

Agreed on doing exactly what the manual says to do while your car is in warranty. You don’t have to get the oil changed at the dealer necessarily, but do keep the receipts if you go elsewhere.

After the car is out of warranty, do what you like.


I have 2018 legacy limited change oil
Every 5;000 miles with full synthetic 0-20

… very likely including the OP’s late-model vehicle.
Has the OP verified–via his Owner’s Manual-- whether his engine requires synthetic oil?
I suspect that it does, but I will yield to the information that the OP finds in his Owner’s Manual.

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I use Mobil 1 in my Acura and change at 5000 without fail. I think extended mileage was a marketing hype because the cost was much higher and needed to make it seem cost effective. People that were more interested in delaying maintenance jumped on it. Of course JMHO but I have had no adverse effects in the somewhere around 150K mileage using synthetic.


I once had a new Volvo. I paid for oil changes. Interval was 3750 miles. The very next model year, Volvo included early oil changes. The interval then became 7500 miles.

What does the owners manual say?
How long do you plan on keeping the vehicle?

I guess it depends, is there a mileage or time period in the owners manual or does it just say go by the OLM which all cars have nowadays . The only issue I ever saw with synthetic was in our 96 Voyager with the 3.0 Mitsu V6 in it . Always had run dino oil and it was fine , tried Mobil 1 of the same viscosity and that thing sounded like a diesel when you started it . Needless to say it was a quick oil change for that .

I’d follow the manufacturer’s oil change interval independent of the type of oil you use. You just can’t recoup the price of an increased chance of engine repairs by deferring oil changes. 5-6 k miles between oil and filter changes seems a reasonable interval.

Do you have the 2.5L or 2L turbo engine?

2.5 L runs great, service manual recommends 5500 mile change, but does not specify type of oil

The service data I’m looking at for the non-turbo 2.5L engine refers to something called the “H4DO” oil specification. From what I can tell that means 0W-20 synthetic, API service level “SN” or better. I believe all the major brands with 0W-20 viscosity are synthetic.

Thank you. You have been a help. Lou

You need to look at page 12-5 of your owners manual. Your quick start guide says

“- 2.5 liter DOHC Non-turbo models use 0W-20 synthetic, replacement interval 6,000 miles under normal driving conditions.”

After reading the owners manual and maintenance guide for your vehicle, I agree with texases that you need to change your oil every 6,000 miles and use 0W-20 synthetic.

I’m a big believer in following extended oil change intervals if and only if the manufacturer recommends it.

I’m surprised your Subaru is still using 6,000 miles intervals. Subaru must know something about that engine that we don’t know.

Thank you. I found it. I need to read more. Lou

Thank you for the details. I appreciate your input .

You REALLY need to read both the Owner’s Manual and the separate booklet that details the maintenance schedule and the vehicle’s various warranties.