WHAT OIL SHOULD I use in my Buick lesabre custom V6 conventional or synthetic

it should tell you on the oil tank

Check the chemistry all oil comes from the same sources, No such thing as Synthetic oil.. Really! speak with a real Petro Chemistry professor...During the refining process an addition chemical step is taken now it's called Synthetic oil. Use API or use whatever YOU think is best. Oh, a seal leaks or doesn't oils not the cause.Regards

I would run conventional to avoid seal seeping. Just change it regularly and use the recommended grade.

Interesting comments on the oils. That is one way to describe Synthetic oils, as Auto_Centric has described. Oils have come a long way and I believe either or in a good brand name are good oils. Synthetic oils are not a petroleum base oil as regular conventional oils, and are chemically made oils. They do have a tendency to find a weak spot in seals and seep threw. Thus seal softeners to add into the oil. Doesn't always work tho. I built a new motor for my truck and I am running it on Synthetic oil, and it leaks a tiny bit out of the front seal. I know the manufactures of new vehicles are sending them out the door with Synthetic oil in them now. Synthetic oils now blend with conventional oils, so you do not have to stick with it. On your vehicle and on most vehicles now a days run 5W30 oil. My motor is built up so I like running 10W30 Amsoil.

Of course more to this subject, I agree with you there Bob, on an older motor cleanliness of the inside of the engine determines for me if to use Synthetic oil or not, I had tried it in my motor of 157,000 miles, big mistake. Thats why I built a new motor. I believe the motor should be pretty clean to use Synthetic oil over conventional. I just don't see anything wrong with using a convention oil for the life of a motor. Now a days I think it is a matter of choice.

I agree, Rowefast. I use Motorcraft Synthetic blend (it is mostly conventional oil) in my vehicles that are naturally aspirated, but I use full synthetic in my Ecoboost powered pickup that is turbo charged. Conventional oil that is changed per the manufacturer recommended interval or sooner will make today's engines last many miles.

In my opinion synthetic oil works well with older cars! Better protection and last longer. Don't believe me, Buick Lesabre 02 used conventional oil at first couple changes after purchase and the change oil light comes on at around 3000 miles! Now I predicted that I could at least get 5000 miles off of good synthetic plus I deliver food so that can be hard on the car. So explain to me why my change oil light comes on at 5000 miles? That's because the car is made to know the oil grades! These cars are built for this oil and had the highest viscosity meaning less likely you'll damage the engine during an unusual cooling issue high heats! Facts so if you did get a vehicle that had sludge you got a car from a lazy person that's all!

As far as I'm concerned only one of you answered the persons question. Bunch of know it alls!!!

According to the 1997 Buick LeSabre Owner's Manual SAE l0W-30 is best for your vehicle. However, you can use SAE 5W-30 if it’s going to be colder than 60°F ( 16” C) before your next oil change. When it’s very cold, you should use SAE 5W-30. These numbers on an oil container show its viscosity, or thickness.

NO not all oils come from the same place. Quacker state oil comes from Pennsylvania and has a lot of sulfur in it. Multigrade oil has teflon in it, need I go on? Not all oil is equal. Amsoil is pure synthetic, meaning Man Made and not from the oil well made. This oil destroyed two engines of mine, however that was years ago, maybe they fixed it. What does oil do? It provides a thin film between two metal surfaces to prevent metal to metal wear. Some oils do better than others. Look at some of the economy cars, really 0W20? Yup and it works, however do not put that stuff in your truck.

Conventional with a little synthetic Blend oil to help out blend according to your driving wear and circumstance use 10w30 though ..... or just use a synthetic blend altogether but I wouldn't risk a full synthetic change might try blending just a little synthetic for a little protection etc.

I have a 2003 LeSabre Custom with 118,000 miles on it. I bought it about 2 years ago with 110,000 miles on it. Because I use the car for "severe service," and because I've used synthetic in all my cars going back to 1984, I'm using a good, full synthetic in the Buick. I've chosen an oil designed for high mileage cars, Mobil 1 High Mileage formula, and it works just fine. There is no seal leakage, oil usage is but 1/2 quart in 3000+ miles, and the car runs great. Because I drive so little, my oil changes are about once a year. The oil life gauge tells me that, at 3,200 miles since my last change, the oil has 44% of its life remaining. I hope this helps a bit ...

Car calls for 5W30 I suggest using a synthetic blend I use Castrol gtx myself that's all mine has seen since brand new and I average well over 24 mpg city with original everything but plugs and wires at 200k miles

It dont matter oil is oil either its gonna regular oil or half or full synthetic dont matter regular oil can take punishment past the oil chamge date but synthetic helps lubricate your motor which is better mpg