Slighty Off topic: Synthetic Oil after using regular

[280z1975]

Ok, this is slightly off topic, but still has a Z angle and twist to it ...

On Wednesday I am going to be driving 1,600 miles to bring my 96' Nissan Sentra to where my fiancee lives. The car has been on regular oil for a while now 135,000 miles (85% highway) but I would like to switch over to synthetic. I was looking at Mobil 10w-40 high mileage blend. Is this a good idea, or should I stick with my old oil because switching over could lead to leaks?

Now for the Z angle ... my 75' 280z. I want to run synthetic on it when it's all put back together. The engine was rebuilt only one year before it was parked and was only driven to school or work by the PO. Which oil route would you guys suggest?

Thanks for the help.

[sblake01]

The main advantage of synthetic oil, from what I've read, is longer mileage between oil changes. I've always used regular oil and done regular oil changes with no oil related problems. I'm really not certain the the extra mileage offsets the extra cost.

[Marty Rogan]

The main advantage of synthetic oil, from what I've read, is longer mileage between oil changes. I've always used regular oil and done regular oil changes with no oil related problems. I'm really not certain the the extra mileage offsets the extra cost.

I have also heard that synthetic oil helps on cars that have chronic overheating problems. My '71 was given a diet of synthetic oil for years from the PO, so I stuck with it. Even at the race track, the car has not run too hot.

Just my 2 cents.

Marty

[Arne]

Synthetic does run cooler, and has less friction as well. I don't yet run it in the Z, as I've only put 50 miles on it and really don't know the true condition of my engine yet. I do run synthetic in all my other vehicles though.

[LanceM]

I run synthetic in two of my trucks. With that many miles on the engine you would probably be better off sticking with what you have been using. On higher milage engines you usually find all of the bad seals when you switch to synthetic, it tends to leak out of places regular oil didn't.

[lordbiotree]

Some people like synthetic and some don't. Here is the reason why I don't use synthetic.

Dirt and fuel gets in oil. Fuel is a corrosive. Fuel separates from oil and is a non lubricant. Do you want to be pumping corrosive causing elements around your engine for 5-10,000 miles? Some people will even go 15-20K on an oil change

Do as you wish. I use valvoline 20W50 High Miles. I've switched to valvoline from Castrol because valvoline is refined in the United States:classic:

Here's some links

http://www.bobistheoilguy.com/ ( Great site. This guy has done lost of tests to back himself up)

http://www.micapeak.com/info/oiled.html (More Than You Ever Wanted to Know About Motor Oil)

http://motorcycleinfo.calsci.com/Oils1.html (All About Oil)