Changing To Synthetic Oil

Hi J.R

I would stick to 3000 miles,to reduce carbon deposit build-up in your engine,as well as piston ring wear..Also,flush your engine with a cheap clean oil(fill up and let your car's engine idle for about 20 minutes),before draining that and topping up with your new choice of lubricant. you will have a performance and fuel economy increase,almost guaranteed!

If one is going to change synthetic oil every 3,000 miles or so, what's the advantage of going to synthetic oil? Am I missing something here? For most newer cars, the mfg'er suggests petroluem based oil changes at 5,000 to 6,000 miles, but a 5W30 or similar oil. Perhaps with older cars, one would like to increase the viscosity a bit.

Spot on!

Whoa! Steady on, it's not quite so simple. First off, how many miles have the engines done on mineral oil? If they have done a lot, you will have problems with sludge. For more info see this site!

Once you have changed over, change it when it gets dirty. I was on once a year with an '89 Honda engine that had done 157,000 miles, this was about 12,000 mile intervals. My wife has a small fiat that only does short journey's, I change that every 6 months, about 3,500 miles, but I only change the filter every 2 oil changes. This is more often then necessary, but then, I don't have to pay for the oil!

JR,

I can chime in on that since I have done that many times on older Porsches. My change intervals are about 5K miles. The manufacture recommends about 10K, but even at $4 per liter it is cheap insurance to change early and my car takes 11 quarts per change. I would also stick with the OEM filters at each change.

Changing to synthetic with an older vehicle can bring on the onset of seal and gasket leaks. I have had this issue first hand. The synthetic seems to a better job at scrubbing dirt and gum out of the engine and the gaskets and seals will sometimes begin to seep oil. Be prepared to deal with this if it happens.

The likelihood of this happening is dependent on the age of the seals and gaskets and how long conventional oils have been used and the contamination levels in the engine. Not everyone has had this happen, but enough people have reported it, so I consider it a wise thing to be aware of.

hii , my advice is to flush your engine with acheap oil first and then use the new engine oil provide that u must change over the filter .

If your vehicles have clocked over 100,000 miles and the engines are in reasonably well maintained condition, I would recommend an oil change period of 20to 25, 000 miles, from the change-over ,since synthetics last that much longer and can give you the performance without losing their potency (if not longer) , desired.

I had an 90 olds that had the fancy electronic enigine monitor system and i could tell about ever 3500 miles on mobile one synthetic the gas milage would go down so i would change it then. Also most synthetic oils have addressed the seal problem with a new formulas, i know mobile and castrol dont have that problem anymore.

First I have 303,000 original miles on my Pickup and it still don't burn oil. My dad is a retired lubrication engineer. This is normal for us.

First the sulphur in your fuel causes most of the wear. When you stop the engine and it cools, moisture condensates in the oil. If you drive short distances the oil does not get hot enough to boil off the water and on cooling more water is added by condensation. Add water, hydrocarbons, sulphur (in blow by), with heat and you get sulphuric acid rusting out your tail pipe.

Your oil filter is a gross strainer only stopping big chunks on the chemical level. What it is very good at is the paper absorbing the acid. The bigger the filter the more paper the more acid it can absorb.

Once the paper is acidified the oil is next. Most oil is a base viscosity boosted with an additive package. The additives absorb some but it is limited. Now it starts micro pitting the metal and with the oil weakened wear is accelerated by many times.

Oil analysis is expensive and complicated but will tell you what is going on if you can read it. For most people it is not an option.

Our rule of thumb, If you drive regularly less than half an hour running time change your oil regularly. The higher the humidity the more often. If you drive longer than a half an hour, 90% or more of the time change your oil every six months with a high quality oil.

Put the largest quality oil filter that will fit on your vehicle and make sure it's a paper element.

You still need to check the Oil, Battery, etc.

When we owned a Trucking company we several times put a million miles on the semi's engines with good drivers. ( the bad ones broke something major like the semi truck first)

This has worked for us for the last 20 years my truck is a 1989 and is drove daily.

My question is do I rebuild the engine when I restore the interior and and electrical that are showing their age?

Hope this helps

Two cents from Brad (ok 4 bits worth)

If you have been religious in oil changing up to now, take the car for a normal run and drain the mineral oil while hot (with gloves on!), let it drain for a long time say 1 hour. The engine will be much cooler to work on.

Change the filer ONLY with OEM, no substitute (this goes for any car and any oil change, what you save is peanuts and it could cost you an engine! Same goes for brake parts!)

Replace with synthetic oil, run engine for about 30 seconds (tick over only please, no gas to start either!!)to fill filter, check level and top up if needed.

Go for between 15-20,000 miles between changes, remember to watch usage of new oil, it should be less than half of mineral oil approximately (assuming same conditions of course). Note miles on day of change and make note of when next change is to be made.....put near to mileage counter on sticky backed paper for all to see....

Expect less engine wear and less top ups(but check anyway till you know everything is AOK) and less old oil to get rid of in the proper manner.

On synthetic oils I have had several cars goto well over the 300,000 KM with no signs of having any problems at all and many cars up to 125-150,000 KMs that were basically just nicely run in when I sold them. 4 x VW and 3 x Mitsubishi, all diesels except one petrol Mitsubishi in the last 17 years, all bought new except one Mitsubishi Diesel that was broke (cylinder head cracked) when I bought it with 90,000KMs and it ran till nearly 400,000 after being repaired by myself!!

A great move that more people should make, you will not regret it!!

Andy, yes, you spelled mangle correctly. As in the phrase "my wife was able to mangle another manual transmission."

On that thought, what the heck is a "chocolate gearbox?"

My VW Passat uses 0w-40 synthetic and says 5000 mile oil changes. Most modern engines have much tighter piston ring groove tolerances, so this is where the more frequent oil changes and lighter weight oils come into play. If you use too heavy an oil or allow the oil to get really dirty then the rings will sieze in the groove and wear the cylinder to an oval.

I noticed in my wife's old Mazda MPV that using 10w30 instead of 5w20 caused a valve train rattle that would wake the dead. I had to change out the new 10w30 and go back to 5w20 that evening, it was that bad. The lighter oil cleared the problem up immediatly.

My Mazda Miata calls for a 7500 mile o/c. The Porsche Cayman says 20k miles - not that I own one!

So I'm pretty much changing synthetic oil at 5k miles on all the cars. I haven't had an engine failure yet. Touch wood....

Thanks, you saved me from "Mangling" anymore English words!!!

I met Tom W. several times when he raced RX7s for Mazda.....the boss at Mazda UK was a neighbour of mine at the time.

The racing RX 7s were a treat to drive.....on normal roads even...

In addition to what type of oil to use and change intervals, a water removing spin-on filter is the answer for moisture issues. Corrosion from moisture is a huge factor when it comes to engine life. The desiccant embedded in the filter membrane absorbs condensation that forms thus reducing acid build-up. This type of product is available in Canada and the US for around $25 - $30.

Well put, but only really needed if you are a 5 mile a day or less driver.....-

20 miles or more boils off the water.....

I think changing engine oil every 3000 to 5000 miles is WAY too often. For about 30 years now, I have changed my oil in 15,000 to 20,000 mile intervals, with no noticeable drawbacks. I do not get much varnish buildup and the seals and rings seem to hold up about the same. I get about 200,000 miles on an engine before any leaks or oil burning show up. However, I suspect I would get a little more longevity if I changed the oil around 10,000 miles.

It must be said that about 80% of my driving is on the freeway, about 60 mph for about a half hour. Certainly this keeps the oil in good condition. I also use "premium" oil filters that claim to have a lot of acid neutralizers in them.

On my next car, I plan to use synthetic oil and change it on 40,000 intervals.

Wow, that's impressive. I've always wondered if the more frequent o/c callouts were just marketing trying to boost sales, manufacturers doing a CYA or really necessary. A lot of the information in this thread indicates that frequent oil changes are not necessary if you use quality materials and parts. The only way to really check this is with analysis of the oil to check the chemistry. That's not done very often at the consumer level. There have been some guys on the Toyota FJ Cruiser forum who have checked oil chemistry and the consensus is that longer changes aren't bad, especially with synthetic oils.

I'm starting to think that this 3000 mile stuff is hooey, but it's part of the warranty too. Catch 22!

Industry will almost always choose the "safe" position. Why would they promote long change intervals and both put themselves at risk of lawsuits or "recalls" of failed engines AND irritate the Oil Industry? Decades ago FRAM came out with the "screen-type" oil filter and had lots of data to show that it would last about 50,000 miles. Yet the auto industry stuck with the 3000-5000 mile recommendation. (I usually leave my oil filter in for two oil changes...just remove it and drain it.)

I do not really know enough about the performance of synthetics, other than hearing that their molecules are stable, whereas petroleum oils are a hodge-podge of sorted molecular weights which continually break up and recombine. I will have to be alert for performance date to determine just when I should change synthetic oil. I plan to keep my 1990 Honda Civic (380,000 miles) for at least another year, so I have time to watch.

You said:-

On my next car, I plan to use synthetic oil and change it on 40,000 intervals.

I tend to agree with all of your remarks, but having had a Touran Diesel with an oil change computer, it recommended a change at between 32 & 36,000 KMs, 40,000 Miles I think is too long for Synthetic....but as you have low speed limits, I could of course be right off track!!!

Let us know when you do this please......

You didn't say the odometer mileage on your two old cars, but my sense is, that there is more to lose than gain (except misconceived feel-good) by switching on a high mileage car--one which has more good years behind it than ahead. Consider:

If you ever have to add oil between changes--oil that is being lost--you will still have to do so with the more expensive oil (which, in like manner, will also be lost during driving). Better (for slowing oil loss) would be to simply go to a heavier weight.

If you are the original owner and have maintained changes at the 3000 mile interval or better, there is little reason to do other than what you have been doing. Even if synthetic oil could add, say, one day, or one year, to the life of the car at its present age, you would only be able to detect the extra money out of your pocketbook...money that could have gone towards the replacement vehicles.

You can think of synthetic oil as a kind of preservative; but, it will not cure any defect or wear condition in any vehicle of any age. The same as quitting smoking and starting to eat right and taking vitamins will not guarantee an old person will live to an hundred.

So, best apply some common sense and put your money to better use--on other things...in addition to a good quality, but readily affordable, motor oil.