My truck takes 5w-20. It's about time to change the oil on it and we called the dealership to aske them if they used synthetic or conventional and they said they used 5w-30. If I start putting 5w-20 in it, will it hurt anything?

 

I would stick with the 5w-20. There is one or two posts running around the forum about the issue and the majority of fellow Ram owners say that the 5w-20 is the way to go due to the MDS in the 4th Gen. Even my owners manual and the oil cap say 5w-20. I personally go to Valvoline for every oil change, use the synthetic oil, also enrolled in their 225,000 mile engine guarantee.

 

Okay. I didn't know if switching to the oil the truck is supposed to take would hurt it or not because the 5w-30 is what has been put in it ever since it was brand new. Also, when I took college classes for mechanics, my teacher said that if a vehicle has always had conventional put in it and suddenly gets switched to synthetic, it could muff some things up. True?

 

A few dealers try to cut costs by buying a single viscosity in barrel bulk and normally it's not a big deal to use an oil close to what the engine is rated for BUT the MDS system is very viscosity dependent for proper operation.

I know a few years back, a couple 3rd Gen MDS owners had problems with 10w30 oil. 5w30 I've never heard of causing a problem.

My old '04 Hemi (non-MDS) called for 5w30 in the book, also indicated right on the oil cap but late in '05 there was a TSB for '04s came out re-specifying to 5w20 and when I learned of it I switched.

Big fan of Valvoline SynPower. I sent three used oil tests out over the first five or six years I had my truck. ALL full synthetic ALL at 5000 miles. Mobil 1 got fair scores but was recommended I change at 5k. The other two were Royal Purple and Valvoline and both of those tests came back saying based on the condition of the oil at 5k I could go 7k and re-test. I NEVER went more than 5k, but it was good to know the oil could do it. Since SynPower is a good bit cheaper, I stuck with it. You can always find the gallon jugs on special somewhere.

IMO, Valvoline SynPower, a good filter, Wix or anything made by Champion Labs (RP, K&N, etc.) or Purolator and use 5w20 - even if the 5w30 is fine for MDS, the lighter 5w20 will get up a tad quicker to protect on engine startup.

Oh and your teacher is subscribing to an old wives tale. Switching to synthetic CAUSES no problems HOWEVER it can expose existing ones that have gone undetected. Finer molecules can seep through leaks that the larger, inconsistent molecules of dino oil can not. ALSO, synthetics tend to loosen old sludge as it cleans the engine. Rare- but in really badly sludged engines this can cause gobs of sludge to loosen and clog the pump's filter...

 

Lots of info there. I will stick with conventional. So what you are saying is that it would be fine to go to 5w-20?

 

I though the Gen IVs all took 5W20 Synthetic.....??

 

Gen 4's do require 5W20. Doesn't have to be synthetic though. But the thread starter (based on his signature) has a 98.

 

I remember him making a thread saying he bought a 2010. Maybe that was someone else??

 

Well his username, signature and Avatar are all saying 98'. If he has in fact bought a new truck, some updates would make things easier!

 

Mr RAM, please update your Info