I was in a hurry a few weeks ago and grabbed 5w30 instead of 5w20 that Dodge recommends and was wondering if thats ok, so long as when I change the oil next time to use 5w20. I also changed my EGR Valve at the same time and ever since then I have noticed the idle is a tad bit lower than it used to be and was curious if thats due to the different weight of oil.

 

It's fine. There won't be any problems.. A lot of people actually pick their oil due to the regional temperature they live and operate the vehicle in.

Viscosity (a fluid's resistance to flow) is rated at 0° F (represented by the number preceding the "W" [for Winter]) and at 212° F (represented by the second number in the viscosity designation). So 10W-30 oil has less viscosity when cold and hot than does 20W-50. Motor oil thins as it heats and thickens as it cools. So, with the right additives to help it resist thinning too much, an oil can be rated for one viscosity when cold, another when hot. The more resistant it is to thinning, the higher the second number (10W-40 versus 10W-30, for example) and that's good. Within reason, thicker oil generally seals better and maintains a better film of lubrication between moving parts.

At the low-temperature end, oil has to be resistant to thickening so that it flows more easily to all the moving parts in your engine. Also, if the oil is too thick the engine requires more energy to turn the crankshaft, which is partly submerged in a bath of oil. Excessive thickness can make it harder to start the engine, which reduces fuel economy. A 5W oil is typically what's recommended for winter use. However, synthetic oils can be formulated to flow even more easily when cold, so they are able to pass tests that meet the 0W rating.

Once the engine is running, the oil heats up. The second number in the viscosity rating--the "40" in 10W-40, for example--tells you that the oil will stay thicker at high temperatures than one with a lower second number--the "30" in 10W-30, for example.

 

I run 5-30 in my 4.7, no problems. Like he said, it all depends on the temps where you live (im in florida so no extreme cold)

 

Personally I'd run a fully synthetic in that sexy block of metal you call a Hemi.

 

Nice info rydesolow, I never new what any of that stuff meant. I just new one was thicker than the other.

 

Anytime my friends And Shiloh 24, my best advice for you, having a 360 like me, is a Superchips 3815. It will give you a lot more horsepower, torque, throttle response will be way better, it fixes all your transmission shift points, and much more. Best investment I've ever made for my ram. Compare it to.. K&N intake, which costs $250-300. K&N dyno's it at 8 horsepower gain. Superchips 3815, which you can get for $200 about, dyno proven +50 horse +50 torque for our year dodge ram 360's. Cheers

 

Thanks for the responses and Im in South Carolina so, not that extreme cold here, although its going to be in the mid to low 20's tomorrow night and I used fully syn. oil so I may just wait and change to 5w20 in about 5k miles.

 

Read here. That being said, recommended oil for the 03 engine (which is exactly the same as the 04-05) is 5W-30.

 

mine is 5w 30 for my 06. you forgot another little tid bit of info 5w 30 oil is better for the overhead cams needle bearings on a lot of the imports. years ago it was 10w 40 as a good oil for the older cars n trucks not anymore newer models need quicker coverage at start up so 5w 30 is recommended because of the closer tolerances.

 

I was told you can run the 5-30, but the 5-20 will get you better fuel economy, (If that's what your vehicle called for), that's what oil they use when they determine what the epg is for my 07 ford mustang