Time vs Miles With HPL

[Gebo]

With short tripping and number of vehicles, it may take me a year or more to get to 5k on my oil.

In using HPL oil, what would your maximum time to run it before changing it?

I currently follow a 5k/6 month interval using Amsoil OE. Whichever comes first.

 

[buster]

1 year.

 

[racer12306]

I'd bet that Amsoil would last the year as well.

Do you have any consistent long trips? Like a 50+ mile trip monthly or so? That helps.

 

[Gebo]

My longest trip is usually 30 miles. 2 of mg cars only 9 miles 5 days a week.

I do go 50+ miles at least once month on 2 of my cars.

 

[Daverino]

If it was me then I would go by miles alone and ignore time as a factor in making a decision to change the oil. Short tripping of course does require more frequent OCI in my opinion

An exception to this would be under manufacturer warranties where they will be looking for any reason to deny a claim if the owner does not follow their requirements to the letter.

I have never seen any evidence of motor oil being broken down or contaminated by time alone. I have seen Blackstone test old motor oil still in the can and it was as good as it went in decades ago. I have also seen tests by members here on cars that have been sitting for years and it checked out fine in testing, since the motor was protected from elements and contamination getting into the engine.

If any one can point to any study that shows time being a factor in oil losing viscosity or becoming more acidic over time I would appreciate it.

 

[kschachn]

I have never seen any evidence of motor oil being broken down or contaminated by time alone. I have seen Blackstone test old motor oil still in the can and it was as good as it went in decades ago. I have also seen tests by members here on cars that have been sitting for years and it checked out fine in testing, since the motor was protected from elements and contamination getting into the engine.

If any one can point to any study that shows time being a factor in oil losing viscosity or becoming more acidic over time I would appreciate it.

It doesn't. Oil "breaks down" by the action of combustion gasses and water, generally with a little heat. It is why, however, that short tripping is detrimental.

 

[The Critic]

I just changed mine after 10 months and 5K of short trips. It would have taken me nearly 2 years to reach the OEM interval of 10K. The UOA showed 3.3% of fuel dilution, not sure if that number would have risen linearly with mileage.

 

[Gebo]

So 5k or 1 year whichever comes first? Reminder, my newest car is a 2009 and my oldest is 1998.

 

[TiGeo]

I'd go 2 years.

 

[Daverino]

So 5k or 1 year whichever comes first? Reminder, my newest car is a 2009 and my oldest is 1998.

It depends on how much short tripping you are doing, versus normal warmed up engine driving.

If the engine oil never has a chance to warm up, and it is started in cold temps, then you are likely to get condensated water in the oil. You can see this when it gets bad on the underside of the oil cap.

For example if the miles on the oil change are all done in trips of less than 10 minutes, then I would be changing the oil very early. As low as 3,000 miles on the oil change in moderate weather, and even earlier in a cold climate.

But if you are doing these low miles with the engine on for an hour at a time but infrequently (say once every two weeks) then I would stick to a completely normal oil change interval of miles that the manufacturer recommends. No matter how long it takes in years and months.

 

[RDY4WAR]

Even with the short-tripping (which 9 miles isn't that short), I think 2 years isn't out of the question. I would do a sample at 1 year to check fuel and water dilution. If it's not too terrible, continue to 2 years.

I have HPL HDMO 10W-30 in my Tahoe that's been in there since September 2021 with only ~4k miles on it. It's not short tripped though, we just don't use it a lot. When it does get used, it's towing something. I'm not the least bit worried about it.

 

[TiGeo]

Even with the short-tripping (which 9 miles isn't that short), I think 2 years isn't out of the question. I would do a sample at 1 year to check fuel and water dilution. If it's not too terrible, continue to 2 years.

I have HPL HDMO 10W-30 in my Tahoe that's been in there since September 2021 with only ~4k miles on it. It's not short tripped though, we just don't use it a lot. When it does get used, it's towing something. I'm not the least bit worried about it.

This.

 

[The Critic]

Even with the short-tripping (which 9 miles isn't that short), I think 2 years isn't out of the question. I would do a sample at 1 year to check fuel and water dilution. If it's not too terrible, continue to 2 years.

Does fuel dilution rise linearly with mileage? My oil was at 3.3% fuel dilution after 5K, would it have risen to 6% after 10K?

What are the negative consequences of keeping oil with 3-6% fuel in the crankcase for 1-2 years? Even with sufficient TBN, isn’t there still potential to negatively affect seals and for moisture to cause corrosion to other materials?

 

[RDY4WAR]

Does fuel dilution rise linearly with mileage? My oil was at 3.3% fuel dilution after 5K, would it have risen to 6% after 10K?

What are the negative consequences of keeping oil with 3-6% fuel in the crankcase for 1-2 years? Even with sufficient TBN, isn’t there still potential to negatively affect seals and for moisture to cause corrosion to other materials?

With the amount of ester and anti-corrosion chemistry they use, no.

The standard test for rust prevention is an accelerated 4 hour test in freshwater. HPL passes the 24 hour version in saltwater. A little bit of fuel won't be a problem in a 1-2 year period.

 

[TiGeo]

I believe fuel % will vary over an OCI based on how hot the oil gets so read that as...all short trips = more oil and more highway driving/longer drives = less/reduces it.

 

[RDY4WAR]

Pump gas has a very wide distillation curve. Initial boiling point is ~100°F and final is ~380°F with a 50% evaporation point of ~210°F. The hotter you run the oil, the more you'll evaporate out.