Oil change conundrum 3

[RossABQ]

I recently took my '86 Porsche 944 on a 3500-mile cross-country trip. Before the trip, I changed the oil & filter (Castrol GTX 20w50 "conventional" with a NAPA Gold filter made by Wix).

I made the trip up and back in 2.5 days each way, approx. 1500 miles each way, and drove about 500 miles at my destination over a period of a week. This was in August, temps were pretty moderate, under 90 F. the whole time, above 70 at night. This car has a water-to-oil cooler.

Basically, each day of travel I had one "cold" start, and several warm starts. I was cruising at 2,500 RPM (60 mph).

So... "conventional wisdom" would say I have 3,500 miles on my oil, it's time for a change, right? I don't think so, but I can see things both ways.

Compared to driving around town (suburban cycle) for 3,500 miles, I had perhaps 1/100th the number of cold starts; and I have about 30 hours driving time on the oil, vs. 125 - 150 hours. In terms of time, this mileage occured in 10 days vs. 6 months that it would normally take me to accumulate that many miles.

The other side of the coin is, I have 3,500 miles on the oil. I suppose there are going to be a certain number of wear particles generated whenever an engine is running, but again, the amount generated at a relatively constant 2,500 RPM vs. constant cycling in traffic is bound to be much less.

I think it would be a waste to drain this oil. What say you?

 

[MMCswRET1991]

Knowledge is Power

FYI: Vehicles equipped with oil life monitors can not tell the difference in oil quality.

NOTE: Regardless of remaining oil life, GM recommends oil be changed at least annually.

 

[ivymike]

I s[sup]e[/sup][sub]e[/sub] that the NEW formatting tools are not going to waste.

 

[evelrod]

I bought my wife a new 328IT for our 50th wedding anniversary. We were planning a trip but health issues made the new car the best option. Now this 2011 BMW has NO dipsticks. None. The oil level, trans level, brake fluid level, water level... all managed by the electronics. Hell, even the tire pressure is monitored by the damn computer. It has 360 degree radar and a 'monitored' speed control that won't let you get to close to another car without first a warning and then reduction in throttle. OIL CHANGE? The computer figures that out by how hard you drive the car and notify the 'car' and the dealer when oil change is due. At present it says we need our FIRST oil change in 1300 miles on July, 2013. Okay, where does that leave the old farts like me? And Ross, and Pat and, ... oh well!

Rod

 

[drwebb]

Dipstick = Smartphone??

 

[patprimmer]

Well it leaves me buying a different car. The arrogance of them notifying the DEALER about MY car.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

http://eng-tips.com/market.cfm

for site rules

 

[dgallup]

I don't think I'll ever be able to buy a new car again. It's not just these maintenance and "nanny" issues, they all have onboard "black boxes" that continuously record speed, throttle position, ABS, etc. Then in the case of a serious accident, your car's black box is pulled and used as testimony against you in court. Maybe if I marry it then the testimony can be blocked.

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[RossABQ]

My past experiences trying to buy relatively common wear parts for a 8 or 8 yr old car, and finding they are no longer available, makes me wonder what kind of dealer support there will be for all the $$$$ electronic crap it takes for a car like that BMW. Personally, I'm watching for a clean '60's car with a wiring diagram that fits on one sheet.

 

[Tmoose]

A not-old-enough-to-be-a-curmudgeon buddy used to say the only cars he'd ever own would have the key/ignition in the dash. At the time ( 1980s) that meant pre-steering/ignition interface lock etc that was mandated in the early '70s if not before.

 

[evelrod]

It's my wife's car. She loves it. Nuff said. I'm still driving the Dodge/Cummins one ton duelly I bought new in 1991 and it still gets 21/22 mpg at well over 300,000 miles. Repainted in 2001 and it has 'issues' with the headliner, otherwise it's as I bought it, all the hoses except belt, brakes and, tires are OEM. I just cannot see any use (for me, I don't even listen to the radio) for the computer. My son just "sent" a whole list of albums "to the car" for my wife's listening pleasure!

Rod