5W20 vs 10W30 / oil changes

I hate to add to the controversy regarding what type of oil to use. But this past weekend (Feb 10th) on a popular radio program called All About Cars, <a href=http://www.wtdy.com/allaboutcars.htm target=new>http://www.wtdy.com/allaboutcars.htm</a> they were discussing Ford's use of 5W20 motor oil. (The discussion was about conventional oil. Nothing was mentioned about synthetic.) The hosts conclusion is that he would at the least not use 5W20 in the summertime but winter is OK. He did not recommend 5W30 because to formulate 5W30 requires "styrene" which tend to wear out. His suggestion was to use 10W30 summer and 5W20 in winter. [I am no engineer - All Disclaimers Apply]<br><br>BTW, in a magazine article I was reading the other day about synthetics they said that it is OK to switch to synthetic oil at any time. The old myths about waiting for the engine to break in is no longer necessary for today's synthetics. And it can be used in older engines also irregardless of mileage. Today's synthetics contain additives which prevent gaskets from leaking unlike in the older synthetic formulations.<br><br>FWIW, while reading through my Tributes' shop manual I found 2 maintenance schedules:<br><br>5W20 Oil Change Interval(4cy or V6)<br>Schedule 1: 6 Months/7.5K miles (12,000Km)<br>Schedule 2: 4 Months/5K miles (8,000Km)<br>[for Puerto Rico: 3 Months/3K miles (4,800Km)<br><br>Notice the Puerto Rico recommendation. It may be a good idea if you live in Florida or other hot spots around the country.

Isn't "styrene" a chemical that is extensively used to make plastics, rubber, and resins.

Isn't "styrene" a chemical that is extensively used to make plastics, rubber, and resins. I'm no chemist but how can such a compound chemical end up in oil? I have found in the past with 10-W30 oil in our 626 V6 that it was too thick and Castrol even was known to cause wax also known as sludge to build up. It was during the period of tapping in the engine from HLA-hydrolic lash adjuster noise from Mazda they had dealers put 100% pure AFT fluid in to quiet them. I asked a master technician about that and his answer was ATF is very highly refined fluid made for long wear in a transmission and is very slick. I said I cringe at the thought of that being in the engine, his exact reply was go Mobil 1 and all will go silent. Ever since then, I have used that 5-W30 oil year round.....that is until we traded on a Tribute!! I've emailed every top synthetic oil company and only Amsoil emailed a reply stating I should use 5-W30 in the Tribute. Being my preference was/is Mobil 1, their reply was simply use convetional Mobil oil. My dilemma is I have Lifetime free oil changes at the dealer every 3,250 but it does not include synthetic, only Castrol 5-W20 which I hate. I will upgrade the oil and pay the difference but to what? I've driven with synthetic under harsh, hot, Florida sandy dusty conditions in traffic and for heat synthetic is better in my opinion. I would advise anyone to read up on it and make your own informed decision. Here is where I get my oil information.... <br><br><br>Want a great link for technical oil analysis as to the complexity, how viscosity links molecular chains in hot weather to prevent damage....<br><br> <a href=http://www.vtr.org/maintain/oil-overview.html target=new>http://www.vtr.org/maintain/oil-overview.html</a>

I ain't no Chemist either. Thank goodness it's not found in domestic beer:<br><br><a href=http://www.lubrizol.com/products/core/vmodifiers/vmtypes.htm target=new>http://www.lubrizol.com/products/core/vmodifiers/vmtypes.htm</a>

Remember Bob that radio program was refering to conventional "dino" oil not synthetic (Mobile 1).

I know....."dino" is the only one we can use for now and stay "legal" with the factory.<br><br>bob

See msg 2790. My dealer recommended 10w30 in summer.