sythetic oil, pro/con

[ArmsMerchant]

My old mechanic (and he WAS old) said that synthe oil would be wasted in my old car (1991--just turned over 200,000 miles, still looks and runs great).

My new mechanic says just the opposite, that it would extend the life of the engine, and would be worth the expense.

Other opinions?

(rats--just noticed, spelled it wrong in the thread title!)

[Rocko]

It's pretty worthless in older cars.

[Mullen]

I tried Pennzoil Platinum in my truck (2000 Chevy, V6), turned out to be a waste of money. I think it just broke down the seals that the dino oil built up and doubled my oil loss. Ended up putting 2 full quarts of oil in over 3000 miles.

[Professor_Skullsworth]

the only time i feel synthetic oil is really necessary is in a high performance/ high stress engine. in your case it would not be worth the extra money.

[Rocko]

GM heavily recommends using synthetic in their newer turbo stuff, and I'm sure most of the other automakers do to. Otherwise it's a waste in engines that don't require it.

[whocares123]

there are cons to synthetic oil?

[Rocko]

there are cons to synthetic oil?

It's stupid expensive.

[TheGreenDoctor]

What I've heard/read is that synthetic oil should only be used in newer engines due to older engines being built to tolerances that aren't as tight as newer engines. The oil gets into places it shouldn't and breaks down seals and leaks past piston rings and valve guides causing oil consumption problems that aren't a problem with todays engines.

Or something like that.

[Vargus]

My opinion?

When you think of anything like this, you need to look at what's called the "opportunity cost." You are buying synthetic over regular oil, but what are you getting over it's cost? This is a first week concept for an economics course.

Synthetic oil generally has much better hot-temperature characteristics, mid temperature viscosity and flow characteristics, but in your case, it has MUCH better cold temperature viscosity properties over normal oil.

So, are you using your car so much that the cold temperature characteristics would be useful? Frankly, at 200k miles, I don't think so, assuming you use the grade oil that your owners manual prescribes. This is because the bearing clearances enlargen over time, and the higher viscosity you have at lower temperature would better fill the clearance.

But, this is theoretical. Yes, the clearances enlargen over time, but is that enough that your grade of synthetic oil will better cover as opposed to cold petro oil? I can't answer that specifically.

Another specific I CAN give is that I use nothing but Rotella T in my Fiero. This is because the cam lifters are of flat tappet design, so it's doesn't have rollers and you have a lot more friction over the lobe surface. The pre-2009 Rotella T formulations have ZDP which has low high-pressure friction properties which means that my lifters last longer. I've seen cases where other tappets and cams have been ruined because no-ZDP oils have been used.

I'm just saying for informational purposes that you need to know wtf is going on. Now, I would safely say that Japanese designed would be using roller cams, hell, for WAY back. As such, you are safe from that problem.

As such, I don;t think there is any problem with keeping with your current dinosaur oil.

GM heavily recommends using synthetic in their newer turbo stuff, and I'm sure most of the other automakers do to. Otherwise it's a waste in engines that don't require it.

This is really true because in high power turbos the oil is heated to such high temperatures that it can cook off leaving behind sludge. (It doesn't domepletely combust) Synthetic has better high-temperature properties so it won't cook off as easilly. Then again, if you have an aftermarket turbo you should have installed an oil cooler. ;)





Also, I'm pretty drunk writing all this, so if I say something stupid don't be afraid to say I'm being an idiot. We are all bettered when we correct ourselves, right?! :D

[ratfrink]

I read an article in a classic car magazine saying that you shouldn't use synthetic oil in an engine designed for mineral oil, unless that synthetic oil is specifically designed for the engine.

Newer engines use harder metals and have finer tolerances so can get away with using thinner oils with different additives. Older engines have softer parts and large tolerances so basically they need an oil which is thick and very slippery, and modern oil will lead to wear and oil consumption.

I'd stick with the mineral oil. Just make sure you change it frequently and you'll be fine.

[blankooie]

Synthetic if your engine goes OVER NINE THOUSAND rpms or if you have a turbo somewhere in the system.

Or if your really, really hard on it, synthetic won't break down as quickly. Its better in extremely hot climates too.

Anything else - cheap oil.

[MediumD]

My recommendations for synthetic are that you should only bother if you live in an extremely hot or cold climate, or if your vehicle is spec'd for it. In your case, while you live in a cold climate, at 200k on a nonperformance motor, I wouldn't bother.

[blankooie]

Are you using a block heater? 200k in a cold climate..all those cold starts its amazing its still alive.

[ratfrink]

What car is it?

I vaguely remember it being a Toyota Hiace or something like that...

[jimany]

Are you using a block heater? 200k in a cold climate..all those cold starts its amazing its still alive.

...I meant to just quote you... Thanks is far too close.

But he is either using a block heater or magic;)

[whocares123]

It's stupid expensive.

I don't think so.

[windhack]

For the extra life, an lubrication benefits I think it's worth the extra money. I own two cars and my parents own two cars. We all run synthetic. I think it's worth the money.

[AngryOnion]

What I've heard/read is that synthetic oil should only be used in newer engines due to older engines being built to tolerances that aren't as tight as newer engines. The oil gets into places it shouldn't and breaks down seals and leaks past piston rings and valve guides causing oil consumption problems that aren't a problem with todays engines.

Or something like that.

^^^THIS is correct
If you put synthetic in at this point I can assure you that within 1 week you have more oil leaks than you can deal with.
Is this the MPV?

[ArmsMerchant]

Are you using a block heater? 200k in a cold climate..all those cold starts its amazing its still alive.

Oh hell yes--experts say to plug in under 20 F, but even as warm as the forties, it helps.

My sweety has a 1987 Subie Wagon with manual choke and synthetic blend oil (previous owner was a mechanic) and it starts at 20 below w/o plugging in.

[happy_one_hit]

Oh hell yes--experts say to plug in under 20 F, but even as warm as the forties, it helps.

My sweety has a 1987 Subie Wagon with manual choke and synthetic blend oil (previous owner was a mechanic) and it starts at 20 below w/o plugging in.

wow:eek:

...impressive.

WRX wagon?

[whocares123]

^^^THIS is correct
If you put synthetic in at this point I can assure you that within 1 week you have more oil leaks than you can deal with.
Is this the MPV?

I have a 21 year old car I bought last year. I was told it burns and leaks a little oil, about a quart every 2000 miles. Well I think they had been using regular ol' oil in it...when I had the oil changed, I went for the valvoline maxlife high mileage shit, which is synthetic. That was back in september and there have been absolutely no leaks and as far as I can tell, no oil burning, as I regularly check the dipstick and it's always in the same spot. Knock on fucking wood, but no problems here.

[ratfrink]

^ I imagine the old oil was too thin. The thickness of the oil isn't affected by whether it's mineral or synthetic, just the additives that's in it. You can get 20/50 synthetic oil (if you ask for it specially), likewise you can get 0/30 mineral oil.

[whocares123]

i'm pretty sure 5w30 is what they were using and what is in it now.

[ratfrink]

Is it a Ford? 5w30 is practically unheard of in the UK, except for all Fords which seem to use it.