Should i use synthetic or regular for routine oil checks

nothing
synthetic oil is good but it has the same problem as ordinary oil
the additives in the oil are all used up and no longer do what they are there for
neutralizing acidity from combustion
keeping moisture in suspension,retaining tensile strength in the oil film and a host of other additives used to promote longer engine life
regular oil is cheaper so more regular oil changes can be afforded( every 5000 miles )
forget the myth that oil doesn't have to be changed for 12 months or 20000 miles
oil is the most vital component in an engine so changing often is for longer engine life
as a point of interest , when you pull into a shop for a service the oil you will get is ordinary engine oil because if synthetic oil was used , you would scream at the bill and not go back there unless you specifically ask for synthetic oil
simple economics and business sense
more costly than anywhere else = no business

Me i find synthetic oil to be better in winter the engine turn faster in cold start but it mush more expensive to use synthetic if your looking to save money synthetic oil good for 15000 km regular around 5000km use synthetic oil because its better for the engine not to save money

Synthetic oils provide better engine protection. 5 quarts

The best oil is the Synthetic type oil that one can get through Walmart or an auto parts store.
However, if the car hasn't been using synthetic type, it's a good idea to creep up on it using a mixture of synthetic and regular oil.

However, I have a couple of Cadillac Devilles that use regular oil and I've never had any problems with it.

I wouldn't use synthetic unless there is a sticker that specifically says to use it under the hood.

Most American cars don't need synthetic.

Some Porsches, BMW's, Mercedes Benz and higher end performance cars recommend synthetic for use all of the time.
Good luck on choosing the best grade of oil for your Lincoln LS.

AMSOIL or Mobil 1 synthetic oils. Either one. AMSOIL claims to be the best but...in order to meet the standards "all" manufacturers of synthetic oils have to have the minimum oil content mixture to achieve the quality standards.

SJ or SL or ILSAC 5W-30 is the manufacturers recommended engine oil.

Synthetic oil is better than carbon based oil because it is cleaner,lasts longer,more efficient & wont leave carbon build up like conventional oil. But if you ran regular oil for quite awhile, your engine will have carbon build up. Synthetic oil breaks up the buildup. That is good. Bad thing is sometimes that buildup is keeping you from leaking or burning oil. If you switch to synthetic oil keep an eye on oil consumption. If you start using or leaking it out of gaskets or seals, you will need to get it out & put in regular oil. If not, you can go longer between oil changes & your engine will run more efficiently for a longer period of time.

Synthetic oil won't break down as quickly as conventional oil, gives better protection and longer life. Excellent product, I Strongly suggested for those out there who forget to do their oil changes regularly or courier/ work vehicles.
Heres the link to an explaination from Castrol
http://www.castrol.com/castrol/genericarticle.do?categoryId=8264018&contentId=6003233
I use conventional Oil in my jimmy with 5% of Lucas engine oil treatment and service the engine every 3,000 miles. I find it to costly for the Synthetic oil every 3,000 miles, and as for the high mileage oil you can buy. The high mileage oil has a higher fluid retention like adding Lucas engine oil treatment to any conventional oil, so you decide on what type of oil you like to use in your engine.
Good luck and hope this helps.

nope
regular will work just as good.

To switch from regular oil to synthetic is not a problem. After you run synthetic, however, it is not good to go back to regular oil. Synthetic oil is and will continue to be more expensive then regular oil, if this isn't a sacrifice your willing to take, don't make the switch. Good Luck!

I would not change to synthetic. The Paseo engine is not designed for it, and the benefit of synthetic oil will not be realized. Save your money, and stay with the regular oil.