Castrol GTX10W30 10,330 Miles Accord 2.3L 4Cyl

Messages
85
Location
TN
This is a daily driver, commuter, car pooler, and general beater. I've decided to use it as a test mule for various oils. I've submitted a couple of analysis on it previously (5K and 8K miles). This time I went 10K on the oil and the filter had 19K on it as I did not change it last oil change. Castrol Syntec 5W30 was on sale so I put that in it for this go 'round and will run that 10K miles as well. Next will be Penzoil Platinum. The comments are kind of odd from Blackstone. Last time I went 8K miles and the Lead was 14 and they told me to try 10K miles. This time at 10K miles the lead was 18 and they say no more than 7500 miles. I have sent in samples from this 1999 Accord, a 2001 Accord V6 as well as a 2002 Supercharged Toyota 4Runner. ALL showed high lead (21 and 8 respectively). I'm beginning to wonder if Castrol GTX isn't up to snuff. All three vehicles were Castrol GTX 10W30. Without further ado, here's the current analysis: 1999 Honda Accord 4cyl 2.3L EX Auto Oil: Castrol GTX 10W30 Filter: Purolator PureOne PL14459 (19K miles on filter) Blackstone was the lab used. This sample had about 6 months of time on the oil, 10,330 miles. No makeup oil added. Vehicle has 125,453 miles on the clock. It did seem to use about 1qt of oil, but stayed in the safe zone so I didn't add any makeup oil so that I wouldn't contaminate the results. I suspected a coolant leak as the reservoir seem to loose about 8oz. I notice no leaks on the ground and have marked the coolant reservoir so I can keep an eye on it. COMMENTS: When we suspect coolant contamination is a possibility we look for high potassium and sodium. Unfortunately, some oils use sodium as an additive, which is the case with Castrol. You can see that potassium was low so we don't think that the coolant that you lost is getting into the oil. We'll be sure to keep an eye on both next time, though. Lead increased here and is likely due to the longer oil run. This shows excess wear at the bearings so we suggest no more than ~7,500 miles on the next oil. The TBN was low at 1.6 so you had little active additive left. ELEMENTS IN PARTS PER MILLION Aluminum: 4 Chromium: 1 Iron: 11 Copper: 3 Lead: 18 Tin: 0 Molybdenum: 5 Nickel: 1 Manganese: 0 Silver: 0 Titanium: 0 Potassium: 2 Boron: 2 Silicon: 13 Sodium: 166 Calcium: 2473 Magnesium: 9 Phosphorus: 625 Zinc: 817 Barium: 0 PROPERTIES: SUS Viscosity @210*F: 64.2 cSt Viscosity @ 100*C: 11.40 Fuel %: <0.5 Antifreeze %: 0.0 Water %: 0.0 Insolubles %: 0.3 TBN: 1.6
 
Last edited:
Messages
1,408
Location
NH
i could not go that long on oil w/o adding...i would say 7500 is long enough for most cars esp in winter
 
Messages
15,056
Location
Canada
Wear metals aren't that bad, BUT, oil has started to thicken up from oxidization....virgin GTX is about 10.6 cst, and now its up to 11.4. Not a big change, and still WELL within a 30-weight, but it is one warning sign...I'd say 8-9k is about the limit for this oil - not that that's shabby at all! Thanks for posting!
 

Speedy1975

Thread starter
Messages
85
Location
TN
It will be interesting to see how this compares to it's synthetic counterpart (Castrol Syntec) that I'm currently running. I'll monitor to see if the car uses less oil as well as gas mileage. So far I've noticed a 1MPG gain in mileage. I use a Scan Gauge II to monitor and took a 500 mile trip last week on the GTX and this week on the Syntec and it was exactly 1MPG difference. If my calculations are correct, then a 1MPG increase should cover the cost of a synthetic oil such as Penzoil Platinum or Syntec since they're about $8 more per 5 quart tub than standard GTX. On GTX I got 30MPG On Syntec I'm getting 31MPG The tank is ~ 16 gallons That means I can travel 16 more miles on a tank, which is 1/2 a gallon of gas. At $2.40 per gallon I'm saving $1.20 per tank. In 8 tanks of gas I've made up the difference in synthetic vs. dino.
 

FZ1

Messages
4,727
Location
Texas
Not too bad, but the oil is shot. 7500 and change the filter each time. You are right,the synthetic pays for itself.
 

Speedy1975

Thread starter
Messages
85
Location
TN
 Originally Posted By: FZ1
Not too bad, but the oil is shot. 7500 and change the filter each time. You are right,the synthetic pays for itself.
I think the filter was still good. Blackstone says they check for in solubles to check filter status and these were still good.
 
Messages
11,247
Location
PA
Remember, the FMs were long shot in the old oil. You would have to control against the same type oil as-new.
 

FZ1

Messages
4,727
Location
Texas
I think you are right re the filter w/your results. I would just prefer to have all new oil of the same brand in. Just preference.
 

JSP

Messages
127
Location
WA, USA
Did you add 8oz of coolant after 10k miles or was it longer? I have the same engine and I added 16oz after 20k miles, but my UOA reports show much lower sodium. So, I am guessing most of your sodium is an additive in the oil.
 

Speedy1975

Thread starter
Messages
85
Location
TN
 Originally Posted By: JSP
Did you add 8oz of coolant after 10k miles or was it longer? I have the same engine and I added 16oz after 20k miles, but my UOA reports show much lower sodium. So, I am guessing most of your sodium is an additive in the oil.
I added 8oz after the 10K miles. I wonder where the coolant is going? Blackstone says it's not in the oil and i don't find any puddles or leaks.
 
Top