2003 Lexus GS430, Mobil 1 EP 5W-30, 4274 miles

[btanchors]

As part of the 60,000 mile service on my 2003 Lexus GS-430 (which I actually performed a bit early), I had the Engine Oil, Transmission Fluid, Antifreeze, and Differential oil analyzed. This posting is on the results for the engine.

The most recent results are on the far right. I was expecting this UOA to be worse than the preceding ones, because the type of driving during this interval changed markedly from previous UOA intervals. Previously, I used the car for a fairly long commute, with the engine being thoroughly warmed up each time. This UOA reflects a new commute that is only about 6 miles, so the oil didn't get warmed up each time. It took me about 8 months to go 4,274 miles! Despite this severe service, I think my results are still excellent. Comments?

Brand: Mobil1 SS SL Mobil1 SS SL Mobil1 EP SL Mobil1 EP SL Mobil 1 EP SM
Weight 5W-30 5W-30 5W-30 5W-30 5W-30
Unit Miles: 10,002.0 15,007.0 37,682.0 45,263.0 56,775.0
Oil Miles: 5,000.0 5,005.0 7,556.0 7,581.0 4,274.0
Sample Date: 07-28-04 10-28-04 09-14-05 06-03-06 11-10-07
Oil Filter: Lexus 90915-20004 M1 M1-102 M1 M1-209 M1 M1-209 M1 M1-209
--------------- ----------------- -------------- ------------- -------------- --------------

Iron: 14 9 7 5 6
Chromium: Nickel: Aluminum: 5 Lead: Copper: 5 1 Tin: Silver: Titanium: Silicon: 59 22 15 2 16
Boron: 220 225 216 171 73
Sodium: 14 12 11 22 18
Potassium: Molybdenum: 121 93 88 85 103
Phosphorus: 1186 994 1036 967 733
Zinc: 1514 1054 1096 1298 849
Calcium: 3070 3217 2706 2618 2606
Barium: Magnesium: 34 33 31 22 15
Antimony: Vanadium: 1 2 1
Oil Added: None None None None None
Fuel % Vol: Water % Vol: Vis CS 100C: 10.4 11.0 11.0 10.8 10.2
SAE Grade: 30 30 30 30 30
Glycol Test: Negative Negative Negative Negative Negative
TBN[C] D2896: 6.56 7.52 6.14 5.45 5.59
Flash Point, COC[F]: N/R N/R N/R 428 N/R
Total Solids: N/R N/R N/R N/R 0.2

 

[buster]

Results are as good as you could ask for. TBN is still high.

 

[JHZR2]

but M1 EP is terrible stuff... its what, group III? They are ripping you off because despite the results, youre paying group IV prices for a group III... Heavens... what will you do? Those results are just too beautiful to believe.

Just kidding... nice results, I wouldnt change a thing... soon youll be at 4 ppm Fe per 4000 miles...

Best,

JMH

 

[btanchors]

JHZR2 - In defense of those who dislike Mobil 1, and are concerned about Mobil 1 and Fe levels, bear in mind this engine has an aluminum head, and an aluminum alloy block - not a cast iron block. So - That could be why Fe is pretty low.

Having said that, I do plan to continue with Mobil 1 EP 5W-30 in this engine, I think it is working out well!

 

[StoicDude]

Is silicone at 59 or is that a misprint?

I would think that is fairly high, or at least the highest I have seen on here.

I doubt it is due to additive, but you never know with the new formulations and I am not an expert.

 

[btanchors]

Stoic -

The High Silicon initially was due to the use of Silicone sealants used in the gaskets. This is very common on Lexus V8s.

 

[StoicDude]

Thanks that explains it.

 

[Vaca]

Originally Posted By: btanchors
... bear in mind this engine has an aluminum head, and an aluminum alloy block - not a cast iron block. So - That could be why Fe is pretty low.


I believe Lexus V-8s use cast iron cylinder liners, so bore wear should show Fe in an UOA...

 

[JHZR2]

Originally Posted By: btanchors
JHZR2 - In defense of those who dislike Mobil 1, and are concerned about Mobil 1 and Fe levels, bear in mind this engine has an aluminum head, and an aluminum alloy block - not a cast iron block. So - That could be why Fe is pretty low.

Having said that, I do plan to continue with Mobil 1 EP 5W-30 in this engine, I think it is working out well!


but theoretically then you'd be at a higher Al wear number than 2.

Additionally, the rest of the thing looks good. I think youre on the right track.

Best,

JMH

 

[JohnBrowning]

True but it has cast in iron sleeve's,steel rings and all the valvetrain part's are iron and steel.the oil pump is steel as well. So their are plenty of sources for iron wear to occur....Since most iron is from the rings I do not see the head and block material as much of a concern. Few engines today are cast iron especialy the heads!

 

[btanchors]

Vaca -

At first I didn't believe you that the Lexus V8s have cast iron cylinder liners, so I just checked in the service manual. It does indeed reference cylinder liners, although it doesn't say what they are made of - But it probably doesn't make sense to have a cylinder liner on an aluminum block made of anything other than iron...

Also - JohnBrowning - I thought the rings were made of chromium? Are they really steel?

 

[Vaca]

I don't beleive the lexus v8 cylinder liners are anything exotic like on some BMW engines...they're just cast iron.

I believe the rings are a high-chromium steel alloy...not 100% sure on that though...

 

[Jim 5]

Originally Posted By: btanchors
Vaca -

Also - JohnBrowning - I thought the rings were made of chromium? Are they really steel?


I thought I had read that piston rings are typically a steel alloy containing chromium.....but mostly iron. In other words, it is the addition of some chromium (single digit percentages)that turns "iron" into "steel". I admit I could be way off base on this.

 

[ekpolk]

And of course, let't not forget that this engine is one of the infamously clean UZ series Toyota V-8s. We see them more often turning in their amazing results in 2UZ form (the 4.7L found in Tundras, Sequoias, 4Runners, etc.). This is the 3UZ, and a close relative of the truck engine. Oil almost always seems to come out of this engine in almost as good shape as it was when it went in. I ran a fill of GC in our Sequoia for 13 months and over 10k miles, with similar results. BT, you probably don't need to worry about testing this engine again until it gets up to a half-million miles or so, though I realize the BITOG compulsion will probably keep you doing it. Thanks for posting your results.