Citgo Synthetic 10w30, '88 Jeep Cherokee, 4.0l, 4105 Miles

[MNgopher]

Vehicle: '88 Jeep Cherokee
Engine: 4.0l Inline Six
Tranny: 4 Speed Auto

Oil Filter: Purolator Pure 1
Air Filter: Fram
Oil Used: 0.5 qts
Makeup Oil: None

50%City/50%Freeway Mileage.

Period was from 5/05-8/05 in Minnesota weather.

Rot 5w40= Shell Rotella T 5w40 Synthetic
Cit 10w30 = Citgo Synthetic 10w30

code:

---

Oil Cit Rot Rot Rot Univ.

10w30 5w40 5w40 5w40 Avg.

Mi on Oil 4105 3968 4186 4192

Mi on Unit77256 73150 69182 64995

Date 8/05 5/05 1/05 9/04

Aluminum 3 5 3 2 4

Chromium 1 1 1 0 1

Iron 17 47 39 15 27

Copper 4 4 2 3 5

Lead 7 7 5 8 5

Tin 2 2 1 1 1

Moly 27 12 7 4 41

Nickel 1 1 0 1 1

Manganese 0 0 0 0 1

Silver 0 0 0 0 0

Titanium 0 0 0 0 0

Potassium 0 0 0 1 2

Boron 0 0 0 0 43

Silicon 9 13 10 9 11

Sodium 3 8 9 10 8

Calcium 2045 3293 3698 3153 2053

Magnesium 10 16 10 8 199

Phosphorous694 1181 846 897 748

Zinc 883 1413 1049 1022 901

Barium 0 1 1 2 0

TBN 1.6 1.9 1.3 2.9

Vis@100C 10.7 14.2 11.8 13.3

Flashpoint375 405 300 345

Fuel 0 0 4.5% 2.3%

Antifreeze0 0 0 0

Water 0 0 0 0

Insolubles0.4 0.3 0.5 0.4

---

For a first run on this oil, not bad. Wear is comparable to the similar run dated 9/04. The difference was the previous runs were fuel soaked and the HDEO did a nice job with that. I've since diagnosed and replaced my dripping fuel injectors and wallah, no more fuel dilution issues.

Citgo Synthetic viscosity starts at 10.4, so that held nicely during the run.

All in all, looks like it worked fine, the next test will be as the weather cools.

FWIW, the engine idles much smoother than when I was running 5w40, and I did not have any issues with oil pressure fade on long hot runs, which is part of what led me to try the Rotella in the first place. Fuel mileage appears to be marginally up.

[ September 27, 2005, 01:49 PM: Message edited by: 59 Vetteman ]

 

[Al]

Pretty obvious that the thicker oil and higher Phosphorus/Zinc didn't mean squat. I'm sure you are overjoyed with these results.

 

[oilyriser]

Notice how the two samples with higher Fe
(5/05 1/05) experienced winter use, while the lower Fe ones were exclusively during summer?

 

[Blue99]

Thanks, MNgopher, for continuing to update your UOA history on these engines. Good results with the Citgo 10W-30 synthetic.

While most would probably describe the add pack as "weak", it is a 3.4 HTHS oil per the data sheet and Citgo has a good reputation as a blender.

I have a 6 qt case of the same 10W-30, purchased on sale for $2.99/qt at Farm & Fleet. The plan is to run during a late winter OCI & get a UOA for posting.

 

[MolaKule]

You have the Citgo 10W30 listed as Cit 5W30?

Good numbers, whatever it is!

Corrected

[ September 27, 2005, 01:50 PM: Message edited by: 59 Vetteman ]

 

[MNgopher]

If I put 5w30 in the post, I definitely meant 10w30! (I will hve Citgo Synthetic 5w30 results in afew weeks out of my F150

).

Yes, this engine has definitely displayed a big swing from summer wear to periods with cold weather in the Iron department. I'll be curious to see if that swing is diminsihed a bit with a return to a xw30 in the winter, rather than trying the 1 oil all year around approach.

I'm also glad to see that I succesfully diagnosed my fuel leak that I likely would not have known about unless I did UOA's and cahnged my own oil...

 

[TheTanSedan]

Are we going to see longer OCI now that you've found a good match?

 

[NewGuy]

MNGopher -

It is nice to see someone who really takes care of their vehicles. It looks like that Citgo Synthetic really did a nice job in your 4.0L. Your Cherokee has low mileage to be 17+ years old. My old Comanche has 160K on it, but still runs strong.

Question: Did you notice any adverse impact from switching from the thicker 40wt back to a 10W30? Any loud noise or oil pressure issues?

It will be interesting to see how the Citgo performs in the winter. I lived in MN for 2 winters and couldn't believe the difference vs. NC. Those winters are brutal.

 

[MNgopher]

No, no adverse changes from switching back to 10w30 after using 5w40. My main reasons for trying the 5w40 were to see if I got rid a bit of a fade in oil pressure on long hot runs. Everything was still in spec, but it just was more comofrting to keep it rock steady. The Citgo synthetic 10w30 also kept pressures steady, so there went the reason for running 5w40!

For now, I'm going to stick to a 4000 mile OCI as I head into the winter months. If the "swing" in numbers isn't so bad, I'll consider extending the OCI.

Yes, I do have a "low" mileage '88. I got it in 2002 with 38,000 miles on it!