[LovableHuggable]

Originally Posted by Snagglepuss

sythetic is great ,just don't use it if your switching and have an existing oil leak...it makes them worse...and whatever ya do ...don't use quakerstate oil ...worst oil protection ive ever seen after teardown and inspection......If you have an older car or vehicle ..I like to run 20w50w its real thick and offers great protection for older vehicles....Also 1/2 quart of dextron automatic transmission fluid added to a full tank of gas ,will clean the pistons/carburator/F..Injection...

Careful with 20w50 in cars like Crown Vics and Grand Marquis. Those V8s can't handle it and have to have 5w30 or 10w30 at the maximum. I learned this one the hard way thinking 20w50 would help my 277k 1994 grand marquis.

[supermanlives]

works fine. i add some additives.

[supermanlives]

more wear and tear is done on startup. want your ride to last longer use additives and get a pre oiler. then the oil flows before the car starts and there is less wear and tear on engine. you can get manual or automatic ones. i highly reccomend LUCAS products. we tore down several engines at school and compared as the school had race cars. lucas rules

[FreedomFightr]

Becareful, with the revision on Api spec they have taken almost all of the Zinc out of the oil. It has killed alot of camshafts. due to the oil breaking down faster and alot of newer cars have a roller rocker valvetrain. Alot of people have switched to Rotella T. Its oil for diesel's but still has the zinc in it.

[FreedomFightr]

You want to avoid Synthetics when your car is brandnew or engine has recently been rebuilt. Your Rings may not seal.

[pip313]

I know this thread is older but its on the first page so.... Do not ever switch to synthetic if your car

1. has over 130,000 miles (I feel anything over 100,000 but I know people will argue)
2. has had any oil leaks before (synthetic cleans gunk, gunk that might be sealing other leaks)
3. has any noticeable gunk in lifter or rocker valley (synthetic cleans gunk, gunk that will stay in oil and turn it into sand paper and might clog the filter) (just do oil change again real soon and be aware)
4. if your car has a turbo and high mileage (75,000 turbos are very easy to break and clog with gunk)

[terribleone]

i use synthetic,brah.do it

[pearlemae]

I just switched to Amsoil. My car has 69K on it. My mechanic used Amsoil engine flush to initially clean the engine, then the less expensive synthetic. After 5K he'll change it for the expensive oil. The reason is that the first 5000 miles will really clean beyond the flush. I notice that the engine is smoother and runs quieter. My mech says if you have a high milage car thats all sludged up you may have to remove the sludge by hand the flush won't do it.

Synthetics can be used after cars reach 10K miles. The new oil change standards for most cars is 7500 miles. They discovered the 3000 miles deal was just to sell more oild and filters. VW diesel are still 5000 for the older one and 10ooo for the newer ones. They require a special oil to keep the cam bearings from getting pounded out of them. You but it at the dealership for about the same price as other synthetics. Mobile 1 is a good oil. I know of a Ford V6 with 220K on it and is using no oil. They use Motorcraft filters on it with that Mobile 1 Extended and change it around 12.5k miles. It is dirty at that point. If you use a calculator on it, the extended performance saves money. Last summer, their kid ran it out of water and cracked both heads. They had it fixed with two new heads on it and it still tuns good and uses no oil nor does it smoke. I think the synthetic oil saved the rest of the engine! But, you have to choose to either spend a little more for synthetic or replace the car sooner. The hassle of having to find another car is worth the few $$ for me to run synthetic. Go ask a few mechanics. Castrol is good non synthetic oil. I do not like syn/reg oil mixes though. No blends for me...

[hazydreams]

This comes down to a few things, at proper operating temp 10w30 is 10w30, oil is oil. Its how the oil reacts to different temps that separates the men from the boys.

Dino oil will keep its properties and additive package to around 250 degrees F.

synthetic and synthetic blends have a much higher heat tolerance in the neighborhood of 325 degree F or more.

Now before you get twisted and say my engine operates at 180-220 degrees coolant. its not even close to 250 degree F, let me give you a little insight. the oil in most engines is used to provide a fluid bearing for the cams and crankshaft. This is accomplished by the tight bearing clearances being pumped full of high pressure oil creating a near frictionless connection. the pressures of 40-80 psi created by the pump obviously heat the oil. so does the internal friction of your engine and the dynamic forces on fluid bearing. so your engine that is running a little warm at 210 degrees coolant temp is probably cooking the dino oil at 240 degrees on a warm day. 10 degrees is no cushion.

once the friction modifier package and zddp is gone your oil is near useless. I have ruined conventional oil in as little as 500 miles from thermal abuse that you will never see or do on a road car. its consistency and viscosity resemble water at that point. and it wasnt burnt looking either, still amber.

Synthetic and synthetic blends plain last longer and do the job better at high temperature.