Oil change and UOA question

[otis24]

Currently, I have about 6500 miles on my vehicle. I will be participating in the Pennzoil UOA program.

Sunday, I wanted to change oil but didn't have time. My sump was a quart and a half low, so I topped off.

I am afraid that doing an oil sample too soon will give me a false reading since I added 1.5 quarts of fresh oil. I have an 800-900 mile round trip coming up. It will be Hiway miles. Is this enough "wear and tear" on the oil to get an unadulterated UOA? My current fill is a blend of MaxLife HM and NAPA Full Syn. I will be comparing it to PUP.

 

[demarpaint]

They ask on the form if you added make up oil. Tell them how much oil you added and how many miles before the oil was changed. Example: Oil was in use for 5,000 miles 1.5 quarts were added at 4,500 miles. In the perfect world it would be nice to go the full OCI w/o topping up for the most accurate results, but things don't always go as planned.

 

[69GTX]

I would have asked them if it was preferred to sample before you topped off....since you're in their program. They can make the call on which data would be most important to them...pre-diluted or post-diluted.

 

[901Memphis]

Your TBN will be higher than it would have been because of the top off, so if it doesn't use oil on every change there could be some misleading on extending the changes.

For example you could have potentially been almost out of TBN below a 2 and fresh oil might bring it up to a 4 so it looks like it's doing well.

Either way there's more to it than TBN, so you will still see a clear picture of contamination in the oil and metals.

The Pennzoil should have plenty of TBN left anyways after highway miles.

 

[Ihatetochangeoil]

It would be best to do your sampling AFTER you make that 8-900 mile trip.

I do my UOA through Polaris labs, and they request a minimum of 1,000 miles for the oil to be "in use" before a meaningful sample can be obtained. I'm going to presume that with only 6500 on your vehicle, this is an INITIAL oil sample?

If so, expect wear metals to be a little higher than "normal" for your engine; and I don't think you're doing yourself any favors by wanting to "compare" it to PUP; or any other oil for that matter. Do you really even know how much of what you currently have in your crankcase?

Most labs (and guys I've seen here) who do OUA pretty much stick to a single brand and viscosity of oil so that "trends" in wear metals, drops in TBN, and additive metals remain trendable and trackable after getting a few samples to establish a baseline and wear pattern.

If you intend to switch brands, why bother with the UOA? Who is going to make sense of the data for you?

Please do not hesitate to call Blackstone or whatever Lab you're planning on using and discussing your plans. They should never not have time to have a pertinent discussion with a customer.

 

[Linctex]

Originally Posted By: otis24
I have about 6500 miles on my vehicle. .... since I added 1.5 quarts of fresh oil. I have an 800-900 mile round trip coming up. It will be Hiway miles.


1.5 quarts is a lot. Wow.

I would run it past 7500 now.

 

[otis24]

The vehicle in question has almost 125k miles. The oil has about 6500 miles on it at this point. This van, like many Dodge/Chrysler vans, are know to use a quart every 1000 miles. In fact, this was the pattern for my vehicle until I switched to a High Mileage oil. Previously, I had cut consumption to about one quart in 2000 miles. This is my first run of MaxLife. The consumption this go-around was one and a half quarts in about 1500 miles since my last top-off. I will either change the oil out as soon as I return from my trip next week or get a sample at the 7500 mile mark and change out.

My next UOA will be taken at 7500 miles as well. I will run my next OCI to 10k miles unless something comes back on the UOA that suggests that I shouldn't. My only other concern is that there is enough cold weather left to simulate my current driving conditions (extreme cold and short tripping) so that the UOA doesn't show an unfair bias towards the PUP based on less extreme driving conditions. And for the record, I hate the cold!!!!! Me asking for cold weather is like folks in Phoenix praying for a heat wave!

 

[Linctex]

Originally Posted By: otis24
This van,... know to use a quart every 1000 miles. The consumption this go-around was 1-1/2 quarts in about 1500 miles since my last top-off.


Once a vehicle reaches 1000-1500 miles per quart oil consumption, I never change the oil again. ever.

No need to.

 

[otis24]

I can see the logic behind that. While I would never go to never changing oil, I would be more inclined to puch OCIs to the 20k mile envelope, perhaps beyond. Tyere was a Mobil 1 study that showed adding as little as a half quart of fresh oil replinished the additives. In addition, changing the filter helped as well. I think the vehicle in that particular study was at 18k miles on the oil.

The 1000-1500 mile per quart is a situation that I have had good luck remedying with a HM oil reducing consumption to one quart in 2000 miles.

 

[GenaFishbeck]

Hi Otis24 - We recommend getting your oil change done after your upcoming trip. You should be fine to run on the top off. The duration of the trip won’t affect the wear and tear to a point where it would deter an accurate test. - The Pennzoil Team

 

[otis24]

Thanks, Gena. Hope to get the oil changed next week and get my first UOA sent in to Blackstone.