120k miles in a 99 Escort ZX2, should I use synthetic oil or high mileage in my next oil change?

my vote is the non synthetic. for several reasons. one is additional leakage that synthetic can cause by being a lighter weight oil in a engine with older/worn seals, and for the same reason of weight, i don't believe the engine bearings being worn in a higher mileage engine would get the needed protection of a thinner synthetic oil. (weight = thinner/heavier...most synthetic is lighter weight)

i recommend Mobil One Extended Performance oil. I have used the extended performance oil for 5 years or more and haven't had any problems. I own 7 vehicles and I like it.

I also like the fact that I can run this oil safely for 15000 miles that's fifteen thousand miles between oil changes. I ran mobile one oil ( different than extended performance) but had change it at 8000 miles.

figure this regular oil is 3000 miles till time to change and mobil one extended performance is 15000 till time to change. do the math on a extended performance oil change you will see its cheaper to run. it cost about 100 dollars to get it changed here. and conventional oil change is about 40 dollars, 40 dollars times 5 oil changes is 200.00. do the math. you still should rotate your tires every 5 to 6 thousand miles and have the car checked out but your oil is good for 15000.

UPDATE:

dont be scared of wives tales about synthetic oil being lighter in wieght and making the car leak oil

the W in a classification of oil like 10W40 does not mean wieght it means WINTER

as explained here:

The SAE classifications characterises the viscosity at low and high temperature of the lubricant. The grade is given by two numbers separated by the letter W (meaning winter).

The first number, followed by W represents the low temperature viscosity, 5W, 10W, 15W... the lower this number, the more fluid at low temperature the oils, the easier the engine starts.

The second number gives the high temperature viscosity: 30, 40, 50. The higher this number, the more viscous the oil when hot.

so if the oil has a wider range of vicosity LIKE 0W50 its a hell of alot better oil than 10W40 because it has allot BETTER lubercating properties and temperature differences.

Synthetic oil is allot better than your car NEEDS .

Your car will run 200000 miles trouble free on regular motor oil with routine maintaince at the cost of $200 for 5 oil changes

Or you can use ten times better oil for less $100 for each oil change @fifteen thousand miles

you pick your poison, i did and im never goin back

:)

Valvoline makes a high mileage synthetic oil.