Should I use synthetic or keep using conventional?

[Chief115]

I'm gonna be changing the oil in my 99(188k), and had the thought to switch to synthetic. Now everywhere Iv read so far says that both types are compatible and are safe to use. However this is a 90's truck and that info might not be valid. Any thoughts?

 

[jimh106126]

I have a 2000 standard cab with a 5.9. I started Mobile 1 at 1200 miles and the engine is in great shape. I wouldn't be getting rid of it if the trannie would hold up as well as the rest. Im buying a 2012 quad cab this week, and will put mobile 1 in next week.

 

[Chief115]

Now what issues are you having with the tranny? Iv heard some people talk about weak trans. What does that mean exactly

 

[dodge dude94]

I'm running synthetic diesel oil and it's gotta be the best **** ever.....5W40 Rotella T6.



As for transmissions, they don't like being worked hard or overheated. Torque converters are weak as well. But this is an oil thread.

 

[VPRPWRD]

I have experienced oil leaks when switching from conventional to synthetic oil. In the research I did it was suggested that the smaller molecules with synthetic oil is what created the leaks. For that reason I don't recommend switching over after 50k miles.

 

[Chief115]

I read that too, but according to all this research they've said that shouldn't be a problem since they're "fully compatible"

 

[dodge dude94]

They are compatible, but you'll still get leaks from your rear main and pan more than likely because the synthetic gets into gaps and stuff easier.

That being said, I've had no noticeable increase in leaks (the back of my pan and my rear main seep) since changing over to synthetic in January, BUT, I'm also running diesel oil, so that's different I guess.

 

[VPRPWRD]

I read that too, but according to all this research they've said that shouldn't be a problem since they're "fully compatible"

They are compatible as in you can mix them without any side effects, same idea behind synthetic blend oils that you can buy pre-mixed. If you've had relatively trouble free miles with the conventional oil I don't see a huge benefit in changing to synthetic.

 

[Chief115]

The reason I thought about it is because synthetic is suppose to have better stability, and increase friction better then conventional (ie better mpg or less wear)

 

[dodge dude94]

Go with Rotella T6.

 

[Merc225hp]

I am also using a 5-40 full synthetic, I am very happy with it and it leaks no oil at all. I did not like the M1 oil at all. Look at Redline oils if you are going to step up.

 

[BBartow]

This truck will only be getting PYB. If I ever start digging into the motor I'll consider switching to a synthetic, but until then nope.

 

[Stegs]

I always ran Valvoline high mileage 10w30. It was my go-to oil for everything

truck always ran good, always used mopar or napa gold filters


I recently switched to rotella t-5, which is a synthetic blend

My truck leaks a very small amount of oil with it, but not enough to worry about right now


I will say, rotella is some great stuff. When you drive, you can tell the engine loves it

I run rotella t-3 in my charger also.....

From here on, its going to be rotella in everything.

If your on the fence, find some rotella t5 synthetic blend, go to napa and get a napa gold oil filter

change the oil in your truck and drive it.....you will feel and see (oil pressure) is way better than before


My opinion, I view synthetics only for newer motors with tight tolerances, older trucks like the 2nd gens do benefit from a synthetic, but often leak, that's why I would suggest a t-5 blend

once you do it, you will never go back

 

[dodge dude94]

I always ran Valvoline high mileage 10w30. It was my go-to oil for everything

truck always ran good, always used mopar or napa gold filters


I recently switched to rotella t-5, which is a synthetic blend

My truck leaks a very small amount of oil with it, but not enough to worry about right now


I will say, rotella is some great stuff. When you drive, you can tell the engine loves it

I run rotella t-3 in my charger also.....

From here on, its going to be rotella in everything.

If your on the fence, find some rotella t5 synthetic blend, go to napa and get a napa gold oil filter

change the oil in your truck and drive it.....you will feel and see (oil pressure) is way better than before


My opinion, I view synthetics only for newer motors with tight tolerances, older trucks like the 2nd gens do benefit from a synthetic, but often leak, that's why I would suggest a t-5 blend

once you do it, you will never go back

Amen! Running T6 I found that immediately my idle was quieter and smoother and it just seemed to behave better with a more responsive oil pressure gauge as well.

 

[Magnum5.9]

I always ran Valvoline high mileage 10w30. It was my go-to oil for everything

truck always ran good, always used mopar or napa gold filters


I recently switched to rotella t-5, which is a synthetic blend

My truck leaks a very small amount of oil with it, but not enough to worry about right now


I will say, rotella is some great stuff. When you drive, you can tell the engine loves it

I run rotella t-3 in my charger also.....

From here on, its going to be rotella in everything.

If your on the fence, find some rotella t5 synthetic blend, go to napa and get a napa gold oil filter

change the oil in your truck and drive it.....you will feel and see (oil pressure) is way better than before


My opinion, I view synthetics only for newer motors with tight tolerances, older trucks like the 2nd gens do benefit from a synthetic, but often leak, that's why I would suggest a t-5 blend

once you do it, you will never go back

Bouncing off your point about oil pressure, any idea what is 'ideal' oil pressure with these second gen? With 10-30w conventional and mopar filter I am usually in the middle between the 40 and 110 so roughly 70.

 

[dodge dude94]

Bouncing off your point about oil pressure, any idea what is 'ideal' oil pressure with these second gen? With 10-30w conventional and mopar filter I am usually in the middle between the 40 and 110 so roughly 70.

That's what mine runs driving down the road, hot with my 5W40 syn.

 

[meistermash]

I went synthetic all the way around. Truck starts so much better when it's 20 below. The rear ends don't make ****loads of noise in the cold either with synthetic or growl until warmed up.

 

[Stegs]

for oil pressure im well above middle


im not around my truck right now, but if 40 is in the middle, im about 3/4 the way up going down the road

im just below 40 at hot idle

im running rotella t5 synthetic blend with a napa gold filter