I like to use synthetic oil, especially in the cold winter months, so I was wondering when it is safe to switch off regular oil. I have 15,000 kms on it now. I have never seen a oil change light on it yet. This will be the second oil change.
thanks.

 

The general consensus is around 15-25000 miles depending on how hard you use the truck. That equates to ~24-40000 kilometers. The harder you use it the sooner you can safely switch over.

 

If you have worked the engine hard then any time after 10,000 miles you can switch to synthetic oil.

 

I've been running Amsoil since 10k and now I have 70k on the truck and all is well!

 

I switched to synthetic at 5000 miles. It was getting towards winter and I wanted the better cold properties of the 5-40 syn. Have kept using it with no problems. I use the rotella syn usually purchased at wally world.

 

patoka pirate,

In case you didn't know but Rotella 5w40 synthetic oil is made from group III base stock. Group III are called synthetic, and have high molecular uniformity and stability. Group III oil bases are used in most synthetic oils and made from crude oil. Group IV are chemically engineered stocks, arguably with the highest performance and longevity. Group III oil can be legally called synthetic even though they are made from crude oil and not chemically engineered stocks like the oils that Redline or Amsoil sell.

 

I don't mean to threadjack here but I got a question. Do the 08's have an oil life indicator?

 

I switched to synthetic at 13K. I bought the truck with 10K on it and it had never been used real hard at all.. was owned by an old guy for hunting.

My first UOA shows that all is well and looking great.

 

My 06 was put on Royal Purple at 5000 miles in Michigan November. It has always been worked towing trailers down 125,000 miles of interstate with 15000 miles oil change intervals.
Best truck--least problem truck i have ever owned.

 

DBLR is right.... Group III is a cheap way out for companies making conventional oils to call a little higher refined oil a syn so they can jack the price up... It is better than they "conventional" oils but if you care enough to want a synthetic oil you might want to look at a high quality group IV or PAO's like what you find in the ones that DBLR mentioned... there is also Royal Purple and Schaeffer.
However if you are planning to trade off the truck in 2 years then you won't really see any real benefit other than extending you drain interval. I generally go 10K on Schaeffer towing everyday... Some people go more but I like to err on the safe side since I am in the oil retailing and servicing business...

OG

 

The group III hydrocraked oils are great lubricants; there is no doubt about that. They are better than the lubricants of yester-year; however the API allowing oil companies to call them “synthetic” is a bit shady.

Back in the day only the group IV and PAO oils could be called synthetic, but then Mobil sued Castrol and lost opening the market to group III oils advertised as synthetic.

Even Amsoil makes a hydrocraked group III line of lubricants; their “XL” series, however at least they tell consumers and price that line lower than their true synthetics.

 

I was surprised today to see Rotella 5w40 Synthetic at $22.00 a gallon. IMHO that's a lot of $$ for Dino oil.

 

I been using Scheaffer's supreme 9000 5w-40 40,000 miles now. Have 50,000 on the truck.

 

Is there any easy way to tell if the oil is group III (dino based) or group IV (fully synthetic)? The castrol, mobil 1, Q-state, etc. that I have all say "fully synthetic".

 

I use Scheaffer's Supreme 9000 5w-40 in my truck also. I put it in when the truck only had 850 miles, and haven't had any problems.