Drain interval recommendation

[Falcon_LS]

Obviously this is going to be based on a used oil analysis of the oil, but I am wondering how long I should run the oil before I send in a sample.

Here's the dilemma. Gas in this country has high levels of sulphur at 500 ppm. In my Grand Marquis, I'm using Euro 4 rated gasoline with an octane rating of 95 RON (91 AKI), and a sulphur content of 10 ppm, and she runs happily on that stuff. But my Montero (6G72 3.0L V6) has advanced ignition timing and is tuned for 98 RON (93 AKI) gas. The available 98 RON has a sulphur content of 500 ppm, and I'm not looking to go back to the stock settings because that makes the truck a dog to drive.

The current fill is Pennzoil Platinum 5w30, which has been in service since June and has just under 4,335 km (2,709 miles) on it, and the engine seems to just love it. Initially the plan was to run this to 15,000 km (9,375 miles) and get a used oil analysis, but after finding out about the high levels of sulphur, I'm wondering what would be considered a reasonable drain interval.

From a financial standpoint, running PP for short drain intervals doesn't make much sense as it costs almost $12 a quart in this country. The other reason I want extended drain intervals is due to time constraints. So I'm considering a switch to a HDEO with a higher TBN content, such as Motorcraft 15w40. Would it be realistic to run the Motorcraft HDEO to 12,000 km (7,500 miles)?

The truck has just under 324,000 km (202,500 miles) on the clock and the bottom half of the engine is all original. If it's of any use, compression figures are 180 PSI in all cylinders, except 3 (179 PSI) and 4 (178 PSI). Thanks!

 

[rclint]

I'm not sure how sulfur levels in gasoline relate to OCI, however when I owned a diesel truck the sulfur level had no impact on OCI ( Dodge 2500 Cummins Turbo Diesel) the sulfur actually added lubrication to the injection pump etc. Maybe someone here will come alone to chime in on the gasoline side of sulfur... but Pennzoil Platinum should be able to run a 7500 mile OCI before sending in a sample.

The Motorcraft HDEO may not be much different in terms of service life than the Pennzoil Platinum, however if it were me I would pull a sample at 6,000 miles. You can spend a boat load of money here, and still not know much more than what you started out with. If you purchased these vehicles in your area of living, and the owners manual was written for that location then it's really hard to beat all the research the manufacture has done to get the OEM recommended OCI's.

 

[Y_K]

Sulfur (depending on what exactly it is chemically) may easily become a TBN eater. Even if this is happening may be not a factor. Too many variables both pro and contra. I would not lose sleep over this.

 

[sangyup81]

Originally Posted By: Falcon_LS
Obviously this is going to be based on a used oil analysis of the oil, but I am wondering how long I should run the oil before I send in a sample.

Here's the dilemma. Gas in this country has high levels of sulphur at 500 ppm. In my Grand Marquis, I'm using Euro 4 rated gasoline with an octane rating of 95 RON (91 AKI), and a sulphur content of 10 ppm, and she runs happily on that stuff. But my Montero (6G72 3.0L V6) has advanced ignition timing and is tuned for 98 RON (93 AKI) gas. The available 98 RON has a sulphur content of 500 ppm, and I'm not looking to go back to the stock settings because that makes the truck a dog to drive.

The current fill is Pennzoil Platinum 5w30, which has been in service since June and has just under 4,335 km (2,709 miles) on it, and the engine seems to just love it. Initially the plan was to run this to 15,000 km (9,375 miles) and get a used oil analysis, but after finding out about the high levels of sulphur, I'm wondering what would be considered a reasonable drain interval.

From a financial standpoint, running PP for short drain intervals doesn't make much sense as it costs almost $12 a quart in this country. The other reason I want extended drain intervals is due to time constraints. So I'm considering a switch to a HDEO with a higher TBN content, such as Motorcraft 15w40. Would it be realistic to run the Motorcraft HDEO to 12,000 km (7,500 miles)?

The truck has just under 324,000 km (202,500 miles) on the clock and the bottom half of the engine is all original. If it's of any use, compression figures are 180 PSI in all cylinders, except 3 (179 PSI) and 4 (178 PSI). Thanks!

Shell owns Pennzoil and makes a great full synthetic HDEO. Are Shell synthetic products available where you are and are they cheaper than Pennzoil?