Moving up in the world

[smokersteve]

I have Royal Purple synthetic 15w40 eng oil in now. I wana be nicer to my truck so Im switching to AMSOIL. Im looking at their site and cant deside on which oil to use.

AMSOIL Synthetic Diesel Motor Oil, Engine Oil

I understand that alot of you use 5W40 or 5W30 but I would like to stick with 15W40 for now. I dont have the bypass yet but once I do, I will use 5W40 or 5W30 cuz it lasts longer(right?) than 15W40.

AMSOIL Products - Auto and Light Trucks Lookup - amsoiloaf.150405366

Thanks

[hpprose]

I personally wouldn't switch. I love Royal Purple and will always use Royal Purple

[smokersteve]

I have never heard that on this forum.

I always hear + about ams

Thanks for the comment

[mustangman02232]

i honestly think synthetic is a waste of money, i run good ole shell rotella and a motor craft filter in all my trucks and change it every 5k. after 3k i wipe the dip stick with my fingers to see if the oil still "webs".

[RescueF250]

Amsoil is not all its cracked up to be in my opinion. Still running motorcraft and running smooth.

[ianstew]

Motorcraft or rotella dino gets my vote. I know synthetics are much more expensive and you shouldn't push an oil change past 5k anyway. Heui injection is real hard on oil. Just my two cents.

[Ratatattat]

I agree that synthetic is a lot more expensive if you are going to change it every 5K, but what is more expensive... changing your oil & filter or taking a sample & doing an oil analysis? An oil analysis will give you the facts on your oil (& filter) and is certainly a much more scientific & cost effective way of determining when your oil needs to be changed. That is why railways, airlines & trucking companies have been doing it longer than I've been alive.
True - I wouldn't bother doing an oil analysis on a little gas engine with 4 qts of oil... it would be cheaper to change it than to test it, but there certainly is a cost effectiveness when a crankcase holds 3 gals .....
How about over 65000 miles on a 7.3 without an oil change? How about over 400,000 on a Mack without a change? (OK, no HEUI injectors there).
Of course, cheaper oils that are prone to shearing (thank you HEUI injectors) would not deliver results like that.

Dino is still cheaper?

With filter changes (as specified by OA), normal consumption (& leaks), there are small amounts of new oil (& additives) being added over the course of time.

As far as the original question, the 15W-40 HD Diesel & Marine oil has the highest TBN, so it is still probably the better choice.

Your mileage may vary.

[smokersteve]

Originally Posted by Ratatattat

I agree that synthetic is a lot more expensive if you are going to change it every 5K, but what is more expensive... changing your oil & filter or taking a sample & doing an oil analysis? An oil analysis will give you the facts on your oil (& filter) and is certainly a much more scientific & cost effective way of determining when your oil needs to be changed. That is why railways, airlines & trucking companies have been doing it longer than I've been alive.
True - I wouldn't bother doing an oil analysis on a little gas engine with 4 qts of oil... it would be cheaper to change it than to test it, but there certainly is a cost effectiveness when a crankcase holds 3 gals .....
How about over 65000 miles on a 7.3 without an oil change? How about over 400,000 on a Mack without a change? (OK, no HEUI injectors there).
Of course, cheaper oils that are prone to shearing (thank you HEUI injectors) would not deliver results like that.

Dino is still cheaper?

With filter changes (as specified by OA), normal consumption (& leaks), there are small amounts of new oil (& additives) being added over the course of time.

As far as the original question, the 15W-40 HD Diesel & Marine oil has the highest TBN, so it is still probably the better choice.

Your mileage may vary.

Thanks for your effort in your comment

I'm eventually going to get a bypass. And for the first few changes I will be doing oil analysis to understand the duration of the syn oil.

It will definitely take a long time for the syn and bypass to pay off but I have NO second thoughts about loving my truck for a long time.

Also oil is not my only money saving approach for long term, not for short term

Thanks for all your comments especially Ratatattat

[tex25025]

One advantage to conventional synthetic oil compared to dino oil is related to the turbo. Most on here know to let the turbo cool down(either by using a turbo time or watching the EGTs and not turning the truck off til they hit a certain temperature), however, you don't have to worry about that as much with the synthetics because of the higher temperatures that they can handle.

I have seen too many oil analysis come back better for trucks that use synthetics as compared to dino oils to think that they are a total waste of money and based on my experience of better cold operations(weather cold) and engine sounding like it's running "smoother", and really good oil analysis has me voting for synthetics. However, I actually run Mobil 1 and that is even more expensive then what has been mentioned.

[RescueF250]

Originally Posted by Ratatattat

I agree that synthetic is a lot more expensive if you are going to change it every 5K, but what is more expensive... changing your oil & filter or taking a sample & doing an oil analysis? An oil analysis will give you the facts on your oil (& filter) and is certainly a much more scientific & cost effective way of determining when your oil needs to be changed. That is why railways, airlines & trucking companies have been doing it longer than I've been alive.
True - I wouldn't bother doing an oil analysis on a little gas engine with 4 qts of oil... it would be cheaper to change it than to test it, but there certainly is a cost effectiveness when a crankcase holds 3 gals .....
How about over 65000 miles on a 7.3 without an oil change? How about over 400,000 on a Mack without a change? (OK, no HEUI injectors there).
Of course, cheaper oils that are prone to shearing (thank you HEUI injectors) would not deliver results like that.

Dino is still cheaper?

With filter changes (as specified by OA), normal consumption (& leaks), there are small amounts of new oil (& additives) being added over the course of time.

As far as the original question, the 15W-40 HD Diesel & Marine oil has the highest TBN, so it is still probably the better choice.

Your mileage may vary.

Ya you do have a valid point. Reguardless that you can go longer distant or miles without doing an oil change, doesnt matter how many times you filter it. Heat breaks down the oil period. Oil so you get analysis oh look oil is breaking down, its nasty, and the truck is running rough. Well personal you know when you change your oil in these trucks you can feel it I dont need an sample to know when I need to. For a DD you dont need a bypass kit.

Railways airlines and trucking companies these motors dont compare complete different built. There are not as complex either.

I pretty modified up in my 6.0 even if I have a oil bypass system I would still change my oil no matter the cost. Simple thing I tell everyone you want to be cheap with a 6.0 you'll pay a whole lot later in the end.

Back on topic its up to you man its your truck, and what you wanna do just invest your money in the right things.