Which Mobil 1 for '03 Dodge Ram

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Jan 23, 2003
I tried the search function and found nothing for this vehicle.
It is a 2003 Dodge Ram with the 4.7 engine.
The owners manual says to use 5w-30 and thats what I have used. It now has 7,000 miles and I want to switch to synthetic. Question is should I go 5w-30 or 10w-30 Mobil 1. Some people say the 5w is a better Mobil 1 than the 10w, some say its the other way around. Veh is used for mostly short trips in the hot Florida weather. Im confused!
Understanding that TECHNICALLY you should use oil in keeping with owner's manual guidance, of the two oils you are contemplating, I would go with 10W30. Given your climate, the type engine and the performance characteristics of the oils, the 10W30, I think, is better for your application. It is more shear stable and has a more consistent UOA track record (as I recall) than the 5W30. If we had more data, and it were easier to find, I'd really like to recommend German Castrol 0W30 BUT at this point I could only advise you based on personal bias/expectation rather than demonstrated performance. As you watch the UOAs become more frequent for that oil, you might want to keep the idea in your hip pocket. Remember, if it proves shear/grade stable, the 0W should not be a concern even in Florida heat, because it is the 30 weight portion of the rating (and the performance of the oil at that end of the temperature spectrum) that will determine the thickness and strength of the oil layer protecting your engine during most of the time it is operating.

[ August 10, 2003, 02:25 PM: Message edited by: pscholte ]
You could use either one of those 2. They're practically the same for all intensive purposes with the exception of better extreme cold performance granted by the 5-30 which you will never utilize in any part of FL. The 10-30, being a smaller viscosity spread will be a more shear-resistant/shear-stable choice. However, again...you can use either...5-30, if you wish to go by the manual.
If your owners manual says 5W-30 I would use it in a Mobil One. HOWEVER in most of my cars that say that, they also say that 10w-30 is just fine given a temp range. Me, I get either or and I mix them at times. I get the one that is on sale at Wal Mart. Sometimes they dont have 5w-30 so I use 10W-30. The only real penality is that the 5w-30 has app .75 mpg better gas mileage.

[ August 10, 2003, 05:52 PM: Message edited by: ruking77 ]
I had a 2001 Dodge Dakota QC with the 4.7. The only thing in that engine that is specificly clearanced for 5W30 is the oil pump(Mopar Magizine). The rest of the clearances are pretty much the same as older LA series engiines. They tighted the tolerances alot but left the clearance pretty much the same. This allows you to run thicker oils like 15W50 just as well as 5W30. THe best place to start with oil for this is 10W30. Get a base line with 10W30 then try 15W50 in the warm months or 5W40 etc.... I ran M1 15W50 in the warm months and M1 10W30 in the winter and my engine loved this combination. My oil pressure always started to rise imediately and it never took longer then 14 sec. to reach full oil pressure even in the dead of winter!

That is one smooth V8!!! Mine never gave me any trouble at all!! It is the best domestic V8 in a midsize truck (Dakota).
I'd go with the 5w30 for a couple of reasons. First, by using the recommended vicosity you are protecting that valuable warranty (keep all oil recepits!). More importantly, you stated the vehicle is used mostly for short trips, so quick start up flow and lubrication are probably more beneficial to you than anything else.
Go with the 10W-30. It has shown time and time again that it outperforms the 5W-30 in UOAs. And don't forget they mostly recommend the 5W stuff 'cause they assume that Joe Sixpack might try to use a dino 10W-30 in Minnesota. You have to take into account the knowledge (or lack thereof) of the masses.

In florida I would also mix a bottle of the 15W-50 M1 with the 10W-30. (Yes I realize I am a brocken record in this area
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