92 Accord 5k Castrol GTX 5w-30

[spinfire]

It has been 10,000 miles since my previous analysis. My trusty Honda Accord now has 174,000 miles. The duty cycle for this interval is different from the previous due to my move to an urban area last year. During this test interval my commute was 3 miles, and the interval period included wintertime where the car barely reached operating temp. I have since moved back to a move rural area and have a 22 mile highway commute, seen at the tail end of this interval. I suspect the hard city driving, short trips, and 3 mile city commute were much harder on this oil. I know that mileage dropped considerably during this time, and it is now much higher.

Here is the analysis from Blackstone: http://isomerica.net/~dpn/D80660.pdf

While the recommendation was for a shorter 3-4k mile change interval, I will probably stick to a 5000 mile interval based on the fact that my commute is now largely highway miles and the car always reaches operating temperature.

 

[Burt]

I question whether premature lubrication failure is the cause. I.e. will there be more wear in the last 1k miles than in the first 4k miles? Or does the iron concentration build to a certain point and it impairs the ability of the oil to lubricate? I suspect not, but I am curious to others' opinions. Goes to the question of whether the analysis is really showing the rate at which the engine is wearing, but not why.

 

[addyguy]

Seems to be a fairly high amount of wear for a 5k run - iron is 5 times what it was before. I guess this shows just how hard short-trip/winter driving is on an engine.

If you've gone back too mostly highway driving, then stay with 5k...if you keep up the short trips, i'd move down to 3-4k. although, on a Honda with 175k, it probably doesn't matter much!

 

[Cup of Joe]

What I find interesting is both runs are GTX but the 1st showed almost no sodium the 2nd has the standard GTX sodium level.

 

[Ausfahrt]

Originally Posted By: addyguy
although, on a Honda with 175k, it probably doesn't matter much!


+1

 

[spinfire]

Not sure about the sodium. The bottles were *probably* from different cases of GTX, though. At some point I accidentally bought a second case before finishing the first and when I moved they got batched back together again.

As I think I said the first time I did an analysis on this engine: I'm pretty sure the body will have long rusted through before the engine fails.

My new commute is 22 miles each way: ~8 miles 60-70mph highway, ~4 miles 50 mph with periodic traffic lights and some stop+go, ~6 miles 60-70 mph highway, ~3 miles 35 mph city, no lights. The biggest wear affecting thing I can foresee there is that the first merge onto the highway happens before the car is fully warm.

Next analysis will show if wear metals go down with the new commute!

 

[FZ1]

Agree with the 5k for highway driving. Just don't lug it.