It is common practice for people to leave their engines in idling mode to warm them up. But doing this takes up a considerable amount of time, wastes fuel and causes wear and tear on the engine.
The modern materials and especially the design of modern pistons and ring-sets mean they can be put under load a lot quicker, and it is advisable to do so.
Modern piston rings don’t seal as good as they should until combustion pressures are up. The only way to get higher combustion pressures is to put a load on the engine.  Cold start up and warming up your engine should include warming up your gearbox and diffs.

The truth about additives is that they are made of substances that do little or nothing for your engine.  They do not enhance your oil’s performance and in many cases have the potential to harm your engine.
In this post I am assuming that you have a modern engine, not a big brown BigCam I, II or II oilcan or an old Detroit ‘no rust’  2 stroke but something from the last 10 or 15 years at least e.g.  S60, C15, DD15, ISX, 6M70, MX13 etc.
Most additives just make your oil thicker, and contain sulphated ash, sulphur, zinc and other additives that kill your DPF and EGR very quickly.  EGR and DPF repairs can then run into $7,000-$8,000.  This also doesn’t include the cost of your downtime.
The trend for modern oils is to be thinner, for better start-up and fuel savings. Most modern engine oils no longer have sulphur, sulphated ash and zinc (that’s why they are called low SAPS), but contain other replacement chemicals.  Adding additives with old fashioned chemicals can compromise these new engine oils and their corresponding new additives. In effect your oil will be downgraded to an old specification and your engine won’t benefit from it and in the long run cause damage. There is a feel good factor here as well, purely emotional stuff – you’re throwing good money away.  The right spec oil for your vehicle, along with correct oil interval changes and maintenance methods are the key.
One would assume that if additives where so good,  the big 5 or 6  oil companies would have killed the additive market already by incorporating all those different  technologies  into their oil.  Not one of them has. They have a vested interest in keeping their oil in your engine as long as possible, saving you money and keeping you as a client.  Some smaller oil suppliers with blended oils and additives also sell add on additives.  They do not include it in their oil because it provided another revenue stream.
If as a vehicle owner you are set on having clean oil, then fit an aftermarket bypass filter.  (I can advise on the right one – just give me a call). These filters used to be on older trucks and made a big difference in engine life. On your new truck it will make a big difference as well because modern trucks are so emission controlled that they put more soot and ash and other contaminants in the oil. This is where a bypass filter really does a good job for you. You won’t go wrong looking at the Luberfiner filters (and no they are not sponsoring this article).  They were the quality choice of filter provided by me when I owned Bay Oil Supplies & Services in Rotorua for 7 years.  You can check them out here: http://www.luberfiner.com/documents/misc/en/FullFlowBrochure.pdf?Cookies=Y (this will open a safe PDF link).

Using the correct oil is very simple.  Buy what the specifications for your vehicle recommend.  Be specification not brand specific.  If  the lubricant labelling states that the oil ‘meets’ the engine oil specification I would generally advise against buying it, unless it was a large recognised brand or had some evidence that would support your decision e.g. an unlimited warranty from the supplier.  If it is not approved by the manufacturer, it is generally for two reasons a) it doesn’t pass, or the manufacturer doesn’t want to pay the fee to the engine manufacturer to have their oil tested.  In some cases approvals are hard to get, simply because the manufacturer has its own agenda.
In some cases the engine you have chosen is not very common, so no oil company will apply for an approval because there simply won’t be a return on the huge fee they have to pay to apply.  These fees run into the hundreds of thousands of dollars in some cases for each test and often renewable annually.
Something else for you to consider is whether your supplier is a reputable company that has a liability insurance of at least 3 million dollars that could be called upon if your insurance company needs to make a claim?  Sadly, there are some sad stories to tell because this factor was not considered by machine owners.
It is recommended that you only buy a brand of oil if it is approved by the manufacturer.
Caltex and the other large branded oil companies have the correct specifications and approvals for their products.  They are able to carry out an audit of your fleet and advise you on what to use.  Unfortunately, if you have more than one brand of vehicle, you will 90% of the time need to stock two or more oils.  This is because of the different engine and emission system design philosophies in America, Europe, Japan and Asia.
Generally cheap product is made from cheap base stock and has so much additive added to the oil that it is like a chemical bath that ruins seals and gaskets. If you work it out over the life of a truck, the right oil provides savings on maintenance and fuel (very little but it all helps) and provides peace of mind.
If there is a problem, hopefully you have a supplier who can arrange for proper testing and  provide reports. I must say that generally an oil associated problem is a thing of the past. 99% of oil problems are about the wrong oil in the engine or gearbox made to do the wrong job.  Stick to product with the right specifications.
If you need general advice I’m happy to help here as well, do not hesitate to contact me. If you have comments feel free, if you’re going to claim your additive works give me some proof from Caltex, or Mobil, or EPA and OEM approvals, not endorsements. If you are looking at extended drain oil intervals this is a good place to start: http://www.aftermarketsuppliers.org/Councils/Filter-Manufacturers-Council/TSBs-2/English/98-1R1.pdf?Cookies=Y