Oil Type regular vs. synthetic

20 years ago I used synthetic and wasn’t sure if I reaped any benefits. I used Amsoil for a while and also Mobil 1 syn. because I could find in on sale. Amsoil was guanteed for 25k miles which I could never let my car go that long at the time. I always changed it at 3000 miles. Now that there are tons of synthetics on the market, and the fact that synthetic oil has been around for a while, what’s the current research say? Worth the extra money?

I think that synthetic is way better than regular oil. I’ve been using it in my Infiniti for a little while now after switching from regular oil and I’ve noticed an increase in gas mileage. Also, check you your car’s manual because I think you are changing it too frequently. My manual says to change it every 7500 with regular oil and I bet yous says something along the same lines. If it does and you feel weird letting it go that long know that synthetic can go for much longer than regular oil.

The current status says maybe. Is it cost effective? That is the biggest question. I say that it could be if you have more than one camshaft in the engine or you have a roller cam like the Chevy V-8 in most of their pickup trucks.

Steep cam angles and every lifter with a roller on it means that I might want to keep things from wearing out. I don’t know how much each lifter costs but it has to be more than the $2 that I was used to. If they are $10 each, it could get expensive for all 16 of them.

Then there is the damage caused when a roller starts to skate or even breaks off. If you want to keep the truck forever you can expect things to wear out but I don’t want anything to break before 140,000 miles when I plan to buy a new truck. I go six or seven thousand miles in one year and I have 60,000 miles to go. If I planned to drive a lot more, maybe I would be willing to pay for repairs and try Castrol GTX or Havoline instead of synthetic.

This overthinking seems kind of twisted but it could make sense, maybe. Somebody else will have to think it from this point on. Maybe somebody who is organized and stuff.

I think we can all agree that synthetic is better. However what better means is questionable. It should give you better mileage, but maybe not enough to notice. It should provide better protection, but how much? I can’t answer those questions.

I can say if your car's owner's manual recommends or specifies synthetic, you better use it. If not, it will not hurt the car to use it.

Now about those 3,000 mile oil changes.  They were fine for your grandfather, but you are not driving a 53 Ford.  Modern cars don't need all those oil changes.  The cars and the oils have changed.  

 [i] Amsoil was guanteed for 25k miles[/i]  Don't believe it.  Look in your owner's manual and follow the instructions there.

Synthetic IS BETTER…But you have to ask yourself is it worth it…

For me…I think it is…

  1. Really helps when starting a car in below 0 temps. Synthetic flows much much better at real cold temps…At -20 regular dyno oil is almost like a paste. For the one winter I lived in Messena NY…we had several days that year with temps below -30…

  2. I tend to keep my vehicles well past 250k miles…Since using synthetic oil none of my vehicles were burning even 1 drop of oil…and some of those vehicles went well past 300k miles…When I was using dyno oil…after 250k they all started to burn a little oil (not much, but noticeable).

Regular oil has come a long long way over 20 years. Synthetic has but not as much.

Changing your oil at proper intervals and topping between with proper one has far more to do with engine life than synthetic vs dino. Unless your specs synthetic it is sort of like vitamins, are they bad, no, do they help who knows.

Is Synthetic Better ? The Owner’s Manuals That Came With 2 Of Our GM Cars Says That The Cars’ Manufacturer Knows.

I gets quite cold this time of year where we live. The Manufacturer of our Chevrolet Impala and Pontiac Bonneville recommends not operating our vehicles without switching from 5w30 to 0w30 (conventional oil) when it’s this cold. Then they say to use 5w30 (conventional oil) in warmer weather . . .

OR . . .

GM recommends 5w30 Synthetic at all temperatures, including extremely cold and hot. That’s what I use. Why try and figure out when to change oil viscosity ? What if the car’s not due by miles, but by ambient temperature ? That’s wasteful.

I operate several vehicles and it’s enough just keeping up on oil changes according to miles (we drive 60,000 miles per year.). I’ve got better things to do than trying to determine when I should change viscosities.

I am sure GM does not make these recommendations just for the heck of it. Besides, if synthetic is better in extreme cold weather, would it not be better in very cold weather ? I think so.

Is synthetic better ? It’s way better for me, no contest. The price difference isn’t enough to fret about. I have priceless peace of mind when we crank up those cars at -20F 0r -30F or a balmy zeroF for that matter !


There are many scientific studies that confirm synthetics are better. But the long change intervals that were part of the early days when synthetics hit the market are history. No maker, marketer, of synthetics would tell you to go 25K miles between oil changes anymore. Therefore the question of whether synthetics are a good value in economic terms is still up to each consumer to answer for themselves.

If you change your oil every 3K miles synthetics are going to be expensive and you are not getting good value from the extra money. If you use synthetic and go the max oil change interval for your car, truck, or SUV it starts to look better.

Is synthetic better ? It’s way better for me, no contest. The price difference isn’t enough to fret about. I have priceless peace of mind when we crank up those cars at -20F 0r -30F or a balmy zeroF for that matter !

That says it all…The price difference isn’t that much to worry about. I average about 40k miles a year…and 5k oil changes…that’s 8 oil changes per year…Since I do the oil changes myself - I’m just paying the difference in what synthetic costs over regular dyno…less then $100/year…INSIGNIFICANT…

I have a hard time believing that, in practice, there’s much of a difference between conventional and synthetic oil when both are changed regularly and high quality oil filters are used. Just from reading this site, I would say that the risk of catastrophic engine failure has more to do with not changing fluids, checking fluid levels, or changing timing belts than somebody using the cheapest API-certified oil on the rack at Wal-Mart.

You were smart not to extend the periods between oil changes.

There are test results published that say that synthetic performs better in lab tests, but I’ve yet to see and data that show synthetic to reduce wear in or extend the life of an engine when compared to regular changes with dino oil. The one caveat I’d make is that if your owners’ manual says that synthetic is required, you should use synthetic.

I’ve personally never owned a car that required synthetic. I’ve owned a number of vehicles into the hundreds of thousands of miles, used only dino, and never worn out an engine. One vehicle ran to 338,000 (it got hit and totalled) and the engine was still running great and not using excessive oil.

The problem with the word “synthetic” is that many people take this to mean the oil change intervals can be extended to infinity, that the oil will remain cleaner than dino oil, etc.
This is not the case at all.

As to whether you need to change your oil at 3k mile intervals that depends on a number of factors; environmental conditions, driving habits, state of tune of the car along with the emissions system, etc.
I don’t have a problem with 5k mile intervals if the bulk of the driving is on the highway.
If it’s stop and go most of the time then the 3k interval should be adhered to.

Note that when it comes to engine sludge, trashed engines, etc. the common denominator is failing to change the oil regularly enough. This means time-wise too so months should be a consideration, not just mileage.

The most cost effective way to maintain your car is to use products that meet the specifications in the owner’s manual. The benefits of exceeding those standards are often dubious.

We used to have a regular on this site (I think it was Rocketman) whose Honda Accord surpassed the 500,000 mile mark. He did it with conventional oil.

It has never been demonstrated that synthetic oil is any “better” than mineral oil…It’s a higher profit product so therefore it gets more and more shelf-space and hype in magazines. Typically, the ENGINE is one of the longer lasting parts of a car no matter WHAT type of oil you use…Just use what the owners manual says to use…Very few cars go to the shredder because of engine failure…Worry about something else…

Current research?? WHAT “current research”…

There is a push to extend drain intervals so that the amount of waste oil and oil filters can be reduced…Some claim synthetic oil can absorb more contaminants before losing it’s lubricating ability and allowing the sludge to build up inside neglected engines. But if you change your oil every 3-4 thousand miles, you are wasting your money with synthetics…

Most drivers will not keep their cars long enough or drive in conditions where the benefits of synthetic will be significant. And conventional oils have come a long way in the last couple of decades, some are very nearly as good as synthetics.

That said, it’s hard to argue with the following:

-Synthetic flows much better at very cold temps compared to dino oil
-Synthetic is factory fill for many performance cars including many exotics.
-Synthetic oil is recommended for turbocharged vehicles and some mfrs. will not honor the warranty if synthetic hasn’t been used.
-Find a racing team that doesn’t use synthetic oil, including NASCAR, F1, drag racing, etc.
-Synthetic lubes are used on the space shuttle.

A year or so ago, I let my oil, Mobil-1 EP, go 8800 miles, then when I replaced it, sent a sample to Blackstone labs. There has been so much discussion on dino vs. synthetic that I wanted to know for myself.

At 8800 miles, FOR MY DRIVING PATTERN, my oil was still in good shape in all parameters. I am south of the snow belt, and much of my driving is highway. I now change my oil at about 8,000 miles. For different people with different cars, and different driving patterns, I would expect different results.

So, most people are guessing. It is okay to guess, it is your car and your money, but when people are guessing, their advice is not worth much to anyone else.

My next experiment involves this very question, whether dino is as good as synthetic. I have five quarts of Quaker State and when it needs changing again, I am going to put in QS dino. But, I am only going to turn it 5,000 miles and have it tested. If dino isn’t as good, I will get it out before there is any damage, and even at 5,000 miles I will be able to see how long it would last.

And, if it is as good, I will be able to project based on the test results.

I happen to believe dino isn’t as good as synthetic, but I want to know so will be testing it to find out.

“Space Shuttle” might not be that good an example.

  • No internal combustion engine, therefore apples and oranges
  • Not the safest ride on the lot (you’ll never guess what they lubricate O-rings with)
  • 1970’s technology

Bicycles (19th century technology) often use lithium grease, which certainly qualifies as “synthetic lube.”

The greatest shortcoming of high quality synthetics has appeared to be in regard to flat tappets but they are fading like L-heads did 60 years ago. Modern engines with roller followers/lifters and close tolerances seem to benefit from synthetic’s qualities somewhat if properly maintained. If the manufacturer recommends synthetics it would likely be beneficial to use it. Otherwise the Texas tea variety is currently a quality product.

I’ve become more of a fan of dino oil after receiving a letter in the mail recently. An oil company is sending me a stipend and a royalty percentage for any oil and gas from a well being drilled about a mile from where I live so knock on wood, I hope it’s big enough to put the Saudis out of business!

A fringe benefit of horizontal drilling. :slight_smile:

My main thought on this is based on the main difference between the two - synthetic doesn’t suffer from viscosity breakdown like conventional oils do. If you are changing oil on a timely basis, I don’t see the need for the extra cost. BUT if your wife is constantly forgetting to get the oil changed in her vehicle (like mine does), then synthetic (and a top quality filter) seems to be the way to go. Synthetic oil is mainly changed for getting dirty, whereas conventional oil can break down over time and lose its viscosity, causing more wear to internal components.