Good dino oil for a boxster with 135k miles

[Yuta]

Please recommand a type of good dino oil for a boxster with 135k miles. I was using mobile 1 high mileage, but heard syn oil is bad for old seals....I plan to change oil every 3500 miles .. is it too frequent? I live in South Carolina, is 10w 40 Ok for autumn use?

[tcora]

Originally Posted by Yuta

Please recommand a type of good dino oil for a boxster with 135k miles. I was using mobile 1 high mileage, but heard syn oil is bad for old seals....I plan to change oil every 3500 miles .. is it too frequent? I live in South Carolina, is 10w 40 Ok for autumn use?

Two very scary words "I heard". Porsche tells you to use synth in the engine, right? Recommends Mobil 1, in fact? Use the type oil recommended in the viscosity recommended by the OEM.

3500 miles might be too frequent, it really depends on time. If you are driving 3500 miles a year, it is a good change interval. I drive about 3500 miles every 3 months, so it would be a waste of resources for me. I recommend starting at the recommended change interval and pulling samples when you change it. Blackstone Labs is well regarded as an oil test facility and their prices are reasonable. You can use the info they provide to decide if changing the interval makes sense or not. Blackstone Labs, no interest other than as a satisfied customer, etc etc

[JFP in PA]

Originally Posted by Yuta

Please recommand a type of good dino oil for a boxster with 135k miles. I was using mobile 1 high mileage, but heard syn oil is bad for old seals....I plan to change oil every 3500 miles .. is it too frequent? I live in South Carolina, is 10w 40 Ok for autumn use?

First, synthetics are not bad for the seals; that is an “urban legend” as the result of the lower surface tension characteristics of full synthetics, which is a very desirable property. Some have noticed oil leaks after switching to full synthetics; reality is that they already had a leak; it just became more noticeable.

Second, there is no "dino" oil that can hold a candle to the heat transfer, lubricity, detergency, and long life under high heat/high shear properties of a full synthetic, unless you go to a "boutique" specialty oil, which ends up costing even more the synthetic.

[MnW's 987S]

The urban legend about synthetic causing leaks also only applied to engines which were originally running dino juice. If the engine has always run synthetic then there is certainly no problem. My Benz E320 is now 10 years old and has 155k on it. Each and every one of those miles have been run with synthetic and the car does not leak a drop of oil. I am sure my 987 will be the same way as its miles add up.

[Brando]

Keep running Mobile 1 as recommended. If anything run a bottle or two of the Swepco Oil Improver that our host sells to add in a good dose of necessary anti-wear agents and you should be more than fine.