Do they have a great product or just a huge advertising budget? Based on there claims this should do a very good job for my truck. Also, with a diesel how long should I wait to change to a synthetic?

I have run it once in my truck. It did not hold as high of oil pressure while towing as Mobil 1. When worked hard in the heat it was a noticeable difference. Since my trucks pressure has always been a bit on the low side I didn't like that.

There are much better synthetics out there in terms of performace AND cost.

Any ideas where I can look for independant testing on synthetics for diesels?

Royal Purple tends to shear down quite readily (oil pressure loss and potentiall increased wear as a result). Despite how they market their product (as a synthetic), it is only a 10% PAO blend.

Any ideas where I can look for independant testing on synthetics for diesels?
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=postlist&Board=25&page=1

Go with Amsoil you will be happier.

Royal Purple tends to shear down quite readily (oil pressure loss and potentiall increased wear as a result). Despite how they market their product (as a synthetic), it is only a 10% PAO blend.

I failed to give them credit for having integrity and not misleading their customers about their spec approvals - RP did pay the $1000 fee to be API licensed after their performance abilities were independently validated.

I failed to give them credit for having integrity and not misleading their customers about their spec approvals - RP did pay the $1000 fee to be API licensed after their performance abilities were independently validated.
That sounds cheap! I thought it cost alot more?

That's what those who want to have an excuse want you to believe. It's in black and white:
Quote from the API on this page:
http://www.api.org/certifications/engineoil/forms/upload/Instructions.pdf

"The EOLCS minimum royalty fee for licensure is $1,050
U.S. for API members and $1,250 U.S. for non-members."

That's what those who want to have an excuse want you to believe. It's in black and white:
Quote from the API on this page:
http://www.api.org/certifications/engineoil/forms/upload/Instructions.pdf

"The EOLCS minimum royalty fee for licensure is $1,050
U.S. for API members and $1,250 U.S. for non-members."

Wow, so now I know how little AMSOIL really cares!

I'm not a big fan of Amsoil. Any other suggestions for oil that I should be looking at?

I run RP in my truck...So I guess I'm a complete idiot....Oh well...:rolleyes:

I run Mobil 1 Turbo Diesel Truck. If I were using Dino oil I would run Delo 400.

Read a wee bit closer. It's $1050 per application FOR EACH PRODUCT SUBMITTED! And that's if you're a API member. If not, then it's $1250 per application.

For each catagory change, or each brand name, or each grade/weight change, there is a seperate application for certification needed. Read the details. It gets quite involved.

For example, consider all the engine, tranny, and gear lubricants that Amsoil has; perhaps 40 or more products? That'd be $50k or more as a non-member.

Plus, there is a fee of 1.5 cents per gallon over the million gallon mark.

Adds up quick, doesn't it? Perhaps now you understand why some companies don't bother with the API rating.

I don't sell or buy Amsoil products, but I understand why their marketing chooses not to seek out the API approval. It's a business choice. It's neither good nor bad, it's just a choice. Means a great deal to some, but nothing to others.

Probably a simple oversight; it's not 1.5 cents per gallon, but rather 0.15 cents per gallon (or $0.0015/gal) over a million gallons - which is a huge volume hurdle. Don't know which small companies are API members or not, if not, the extra $200 for non-member licensing shouldn't break the bank for companies with million+ dollar facilities. If an extra $200 were a challenge for a company, that might make me concerned about their product as well.

Being independently validated is part of the cost of doing business in practically any industry - it instantly validates a minimum level of performance so consumers don't have to decide whether or not be believe a salesman. Some people might appreciate doing business with a company who actually has ethically obtained a performance claim before they tell the world about it; others may not give a hoot as long as a $20 oil analysis report looks good to them. We are all free to choose and engines aren't blowing up.

I run RP in my truck...So I guess I'm a complete idiot....Oh well...:rolleyes:
You aren't an idiot :D

Have you had an analysis performed on your truck with Royal Purple? If so, is there anyway you could post the results here? TIA.

You aren't an idiot :D

Have you had an analysis performed on your truck with Royal Purple? If so, is there anyway you could post the results here? TIA.

I would like to see a RP UOA as well.

I run Mobil 1 Turbo Diesel Truck. If I were using Dino oil I would run Delo 400.


make sure it is the new CJ-4 for the new trucks.