2003 Lexus GS430, 5215 miles Amsoil Signature 5W30

[btanchors]

OK - before anyone criticizes me on not going far enough on this oil - please bear in mind this oil was in service for nearly 13 months. Severe service - I only live 2 miles away from work, and this vehicle was the principle vehicle used to get back and forth to work. It would occasionally get a long highway run, but not very often.

I'm pretty pleased with this oil's ability to stand up to this type of service. I think I could probably get two years of service out of a single fill based on this report.

 

[OneEyeJack]

Is this a trend that indicates that you should change the oil more often if you're going to continue using this same oil?

 

[69GTX]

TAN is quite a bit higher than TBN on all 3 samples. On the middle sample, a TAN of 6.9 seems quite high for a TBN that should still be very good at 5.9. The first sample shows considerable magnesium. Not Amsoil? I don't think I'd go a 2nd year on that oil, especially knowing the trips are usually only 2 miles. I do frequent 4-8 mile single trips and I'm no yet comfortable going a full year.

 

[btanchors]

To answer a couple of the questions...

The first sample showed more magnesium because it was still "washing out" of the engine after having used Mobil 1 prior to that UOA. All the UOAs in this report are on Amsoil.

Also - The virgin TAN for this oil is around 5.0.

 

[Brons2]

Originally Posted By: btanchors
Also - The virgin TAN for this oil is around 5.0.


In that case try 18 months and 7500 next OCI.

 

[timeau]

Originally Posted By: btanchors
Also - The virgin TAN for this oil is around 5.0.

I don't believe in this statement. This is beyond of all possible values. Here is a VOA of Amsoil Signature 5W30, TAN is 1.73.

 

[btanchors]

timeau -

Here is a VOA of 0W-20 Amsoil Signature. It shows the virgin TAN at 4.6...Is this close enough? TAN should be the same as the other oils in the series...

VOA Amsoil Signature 0W-20

 

[Greasymechtech]

TAN/TBN comparisons in UOA vs VOA require the same lab.

Looks great. But, isn't that a trait of those V8's that Toyota produces?

 

[bigt61]

Blackstone is conservative. Follow their advice - two years is not a problem. Your #'s all look fine - good post.

 

[lubricatosaurus]

Viscosity was climbing. You'd think fuel dilution would be more of an issue with short trips, but I'd say your rings are sealing very well (no makeup oil added corroborates that too), reducing blow-by here and fuel contamination.

The Amsoil must have been oxidizing a little, which is usually seen only when an engine is run hot a lot, not for short tripping.

I don't think I'd go 2 years on this oil. You've got the right change interval (about a year) with those short trips you've got.

 

[CT8]

The cost for a year long oil change isn't that high so change the oil. Once a year is east to remember.

 

[901Memphis]

Yes some oxidation thickening but it's not a problem yet. You can go further with this oil or just use the less expensive oil and change it once a year in the spring, I'd use Mobil 1 High Mileage 5w30

 

[gallydif]

Originally Posted By: CT8
The cost for a year long oil change isn't that high so change the oil. Once a year is east to remember.

+1