OCI for low milage car

[dobie0791]

I am running 5w30 conventional Castrol GTX in my 05 Subaru STi. The car only gets driven about 4000 mi per year (not a daily driver). Since I have had the car, I have been doing an oil change every 6 months, with the idea of switching to 1 OCI per year once I go with something like GC at around 8-10K.
This last 6 months I have only driven the car around 1000 mi.- should I change the oil and filter, or just the oil?
It seems like a waste to change the oil & filter when the oil is still golden colored and has so few miles on it.
thanks for any input, mh

 

[huffmuds9320]

My car is also a low yearly mileage car, I do about 2000 miles a year. Mine is 02 VW Jetta 2.0L ~26,500 miles on the odometer. My oil change interval is once a year. I use synthetic for better protection for the whole year plus manual recommends VW approved oil.

Once a year oil change should work very well in your situation since you plan on using synthetic. I'm not very familiar with Subaru, does your STi have turbo? Does the owners manual say change oil every 6 months? You could do an oil analysis and see if a 1 year interval with that oil will work. But color isn't necessarily indication when oil needs to be changed. It doesn't get too hot or cold in the bay area.

 

[Idrinkmotoroil]

only thing you need to worry about is control of acidic compounds which are left sitting for a year with that type of OCI. I don't know if some oils are better at controlling acid/corrosion, I would think a good synthetic is the way to go over a cheaper conventional as they are normally built for longer drain intervals - time wise.

good luck with it.

 

[BlazerLT]

once a year will be perfectly fine for you.

ENJOY that rocket.

 

[UncleRunkle]

I think you'd be fine with once a year and a good dino as long as every time you drove it you got the oil up to temp and to burn off the fuel and moisture. Really a used oil analysis will be the only way to tell.

 

[XS650]

Once a year will be fine, particularly in a climate as mild as Santa Rosa's.

It would be a good idea to drive your car at least 10 miles at once every month so the oil gets up to normal operating temperature and drives off any moisture. Make that 15 miles in what passes for winter in Santa Rosa.

Don't bother with synthetic, you aren't challenging your oil much.

 

[dobie0791]

Thanks everyone. XS650, when I drive the car, it gets driven ;-)It is not used for commuting or grocery shopping. There have been a couple of times that the water temp guage went up a little after hitting traffic during spirited back road romps. I think GC would offer good extra protection when heatsoak rears it's head.
On a related topic, what kind of OCI would you all recommend for a 2003 Mercedes Benz S430? My father bought one 13 months/10,000 miles ago and has not changed the oil yet. He says the manual (or dealer, not sure which) says 12K with Mobil 1. That seems kind of high for a vehicle that is a known sludger. I might head over his house and change his oil for christmas...

 

[XS650]

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On a related topic, what kind of OCI would you all recommend for a 2003 Mercedes Benz S430? My father bought one 13 months/10,000 miles ago and has not changed the oil yet. He says the manual (or dealer, not sure which) says 12K with Mobil 1. That seems kind of high for a vehicle that is a known sludger. I might head over his house and change his oil for christmas...

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Try a used oil analysis now and see what it says, then go from there. I recently had one done on a Corvette with 8800 miles on the car, 8200 on the Mobil 1 oil. The Mobil 1 oil was in excellent shape and would have been good for 12k miles based on TBN, but GMs program of letting the customer do final machining on the engine by driving the car meant I was over due for a change because of wear metals. Mercedes should do better.

 

[Gene K]

Quote:

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On a related topic, what kind of OCI would you all recommend for a 2003 Mercedes Benz S430? My father bought one 13 months/10,000 miles ago and has not changed the oil yet. He says the manual (or dealer, not sure which) says 12K with Mobil 1. That seems kind of high for a vehicle that is a known sludger. I might head over his house and change his oil for christmas...

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Make sure you use the correct Mobil 1! That needs to be 0W-40 (M-B 229.5). If you use another brand make sure it meets M-B 229.5. Castrol Syntec 0w30 "European Formula" is another oil that meets this requirement.

The sludge was caused by up to 20,000 mi OCI with the wrong oil!

PS if you change the oil you are going to need a lot of it. 8.5 Qt if memory serves. You also need a good extended service fleece oil filter.

 

[AndyH]

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I'm not very familiar with Subaru, does your STi have turbo?

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It sure does. It has a 2.5L 4-cylinder turbo-charged engine pushing out 300hp in stock configuration.

 

[Iain]

Quote:

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I am running 5w30 conventional Castrol GTX in my 05 Subaru STi. The car only gets driven about 4000 mi per year (not a daily driver). Since I have had the car, I have been doing an oil change every 6 months, with the idea of switching to 1 OCI per year once I go with something like GC at around 8-10K.
This last 6 months I have only driven the car around 1000 mi.- should I change the oil and filter, or just the oil?
It seems like a waste to change the oil & filter when the oil is still golden colored and has so few miles on it.
thanks for any input, mh

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Also, don't forget about your oil filter.

Most filter manufacturers recommend changing filter at 6 month intervals because of degradation of cellulose filter media. Amsoil recommend 1 year change interval for full synthetic EaO filter.