Extended oil change intervals..

Of course I want to see your UOA, Evan. I want to know why your wear metals are low among Prius!

Did you switch to synthetic at a very low odometer, or do a very early 1st oil change? I forgot.

I wonder if block heaters, foam tubes etc. might actually ever so slightly reduce cold-start wear.

I guess you don't use the K&N engine air filter; the one with the big-a$$ holes (might have to let go of that experiment, someday)

My only concern with these long oil change intervals (when supported by UOA) is that they might allow you to ignore visual inspections of all those safety-related systems under the car. It is good to get down there every 4k. Sooner if you can stand it.

 

What was you TBN in other reports? I keep wanting to see if Mobil One 5W-30 tracks lower than other synthetics. 2.4 seems low compared to others.

 

Evan all I can say about the K&N air filter is that I do use it and I do have a little higher Si and maybe-above-measurement-uncertainty higher Fe and Al. Not enough different to suppose that a wear scar has actually been created on some contact surface, but enough to watch in the future.

People who hate K&N *really* hate them. But I am just trying to understand the long term risk. The long term benefit is already clear: Not a pile of discarded paper airfilters, and a few hundred $.

My K&N has experienced some atypical events because I do (did) drive on the unpaved roads. Very very unpaved. But whenever possible I would lift the accel (and shut off the gas engine) when a Jeep + dustcloud approached from the opposite direction. That should help. But ultimately, we are talking about one wear scar caused by one 'lucky' sand grain that gets through and hits metal 'just right' before the oil filter catches it.

 

Thanks. I will continue to follow.

 

I know I have said this few times but in the UK we go 10K-20K between changes. Surly if you use Mobile 1 10K should be no problem if its the same oil we have. 10K is standard oil change in the UK form the Prius. Gm cars I think are 20K.

 

Sadly, the API American Petroleum Institute has such weak standards, and has so badly brainwashed the average motorist, that folks shiver in fear if they think they have more than 3,000 miles on their oil

When I mention certain cars with LongLife service oils that allow 24 months or 30,000 miles, folks here go insane. Some even claim if they lived in the EU they would STILL change the oil every 3,000 miles!

Just sit back, have a Pint, and laugh. Works for me

 

I just got my UOA from Blackstone - darned fast! Mailed it from Vermont on Sat, got results in email today!!

I'll try to attach it but in case it doesn't work:
I've been using Mobil-1 5-30 since the 10K change, changed every 5K until this sample. This is the first time I have ever had a UOA.
Engine miles: 62,421
Oil miles: 7,400

All numbers at 7,400 miles in line with averages
TBN: 3.7 Their comment said anything < 1.0 is bad. Try 8,000 miles

Heck with that, I can make at least 10,000 Evan's car had a TBN of 3.3 at 7,700 miles and 2.4 at 10,000 miles. Blackstone suggested he go to 12,000. Glad I finally got around to mailing in the sample (took it in March when I changed the oil). I'm coming up on 7,500 on the oil already.

 

Make sure you don't focus on the TBN, but also look at wear metals, flash point and insolubles.

Just because the oil has a good TBN left, doesn't mean that you should run the oil longer.

In your case, it looks pretty good, though I am slightly concerned by the trace of fuel and low flash point. What was your driving patterns over the OCI?

 

From what I have seen, Blackstone is very good at looking at the "whole picture" for oil analysis. They don't just focus on TBN