Change oil now or wait?

[jsharp]

I have one car that hasn't had the oil changed in 13 months, but I've only driven it 900 miles. One trip last summer of about 500 miles and a few times since then about 50-75 miles each time. The car has been sitting since last December.

Oil is 5W30 Mobil-1
Car is a stock Mustang LX-5.0L with 80K miles.

Of course the oil looks just like it did whan I put in in last year. Do I change it now or drive it a while? Opinions??

 

[pscholte]

jsharp,

I say change now...in other threads you have probably seen that it is more than miles that "does in" an oil. I recommend you never go over a year even though you put so few miles on the car in sporadic intervals. I'd say the way you have driven it, you should not have any long-change-interval generated problems, but I would still change it. Now if it REALLY galls you to change a synthetic with 900 miles on it, draw a sample and do a UOA...that will tell you the condition of the oil.

 

[jsharp]

quote:

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Originally posted by pscholte:
jsharp,

I say change now...in other threads you have probably seen that it is more than miles that "does in" an oil. I recommend you never go over a year even though you put so few miles on the car in sporadic intervals. I'd say the way you have driven it, you should not have any long-change-interval generated problems, but I would still change it. Now if it REALLY galls you to change a synthetic with 900 miles on it, draw a sample and do a UOA...that will tell you the condition of the oil.

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My first thought was to change it, and if cost were any issue it's still cheaper to change than to do an analysis. The $ isn't enough to worry about really.

My curiosity is killing me though.

I'm considering running it another 500 miles or so and then changing. I think it might be interesting to send a sample off just to see the effect of these conditions. It would add to the data pool we all seem to pour over anyway.

I'll post the UOA if I decide to get an analysis done...

 

[pscholte]

I, for one, would be enormously interested in what your UOA shows...as long as YOU are making the decision to extend the drain interval.

 

[Drstressor]

It will be fine to run longer. I have gone 25 months between changes using M1 in a Honda outboard that sees little use. The UOA results were fine with the usual "oil is suitable for continued use". You may see high iron because of metal oxidation during storage, but I'll bet the oil will still be well within specs.

 

[Mike242GT]

jsharp:

I would definitely dump that oil now. I previously had some Mobil 1 10W-30 in a vehicle I wasn't driving much. A UOA at the end of 18 months with about 2,500 miles on the oil showed very high Pb. For an infrequently driven or stored vehicle, you want an oil with a stout anti-corrosion additive package, and Mobil 1 apparently isn't it. One of the diesel or "fleet" formulations would be better, although you may not find one in a viscosity appropriate for your application on the shelf at Wal-Mart.