Synthetics in older engines?

Messages
233
Location
Pullman WA
I have two older vehicles, 1989 Mitsubishi Mirage (157,000 miles) and a 1992 Buick Skylark (105,000) I've been thinking about trying synthetic oil in one or both, vehicles however I've heard some people say that it is best to not use synthetics in older engines because synthetics are more "slippery" and will cause oil leaks...is this true? As far as synthetics go has anyone got any feedback on chevron supreme synthetic oil or the wallmart supertech synthetic oil? Thanks.
 

Al

Messages
19,167
Location
Elizabethtown, Pa
The only true over-the-counter Synthetic oil today is probably Mobil 1. The rest are just some form of hydroprocesses oils. Mobil 1, Amsoil, Royal Purple are possibly going to cause you some seal seepage. The rest probably won't. Unless you want jto go extended oil change-moving up to a true syn probably is a waste of your time and money. You can check out the Shaeffer's stuff. Appears to be as good or better than either Mobil 1 or Amsoil-even in the syn blends. Welcome to the boards. There are a lot of knowledgeable folks (not including me here). [Welcome!]
 
Messages
5,785
Location
Dixie
Pretty good specs on the Chevron Supreme synthetic ....I took a look at their 15w-50 recently, which meets the ACEA "A3/B4" classification for high end German engines. The 10w-30 looked pretty good as well ....If you can get it for < $3.50/qt it's not a bad deal. No problem changing over in most engines that are less than 10-12 years old, as long as they have been well maintained. Change oil filters every 3000 miles for the first 12,000 miles after changing over - the synthetic will clean out all the crud from the petroleum lubes .... TooSlick
 
Messages
1,874
Location
Ocala, Florida
Mustang, I myself would not recommend the change over on such vehicles unless... You know the vehicles have been from day one using a good dino and has had excellent service from that day. This will have ensured you don't have build up around your seals and such. If it has crud build up around the seals, the synth will do an excellent job of cleaning it, thus the problem. Not because the oil is "more slippery" as you put it, but the crud has coated your seals and now acts like the seal, but when cleaned it will move back to relying on the actual seal which in a lot of cases have harden due to no oil getting to them over the long time of having crud on them. This IMO is the biggest problem of going with a full synth switchover. I'd advise that you do a purge on your engine prior to doing this switch over with either auto rx or neutra 131. These are designed to do that cleaning passivly but also help get the seals back to being plyable. This proceedure can be done after switching over also, so if you really need to switch over to a full synth, and do it prior to purging, you may or may not get away with the seal issue, but these products should work even after the fact.
 
Messages
3,683
Location
Chattanooga, TN
Based upon my experience in coverting from dino to synthetic in cars I have purchased as used with mileage of anywhere from 30,000-60,000 miles you will get oil seepage at anywhere from immediately to one year after the change over. Almost guarantee you will get some seepage as the synthetic cleans up the seals. I would not change over at the high mileage you have. Now, most of my seepages have been very minor but they still seep oil when they did not before the changeover. This has occurred on all 3 engines that I changed over after purchase where dino was used by previous owners.
 

MustangGT

Thread starter
Messages
233
Location
Pullman WA
If I stuck with Dino on these cars (buick and Mirage) which Dino would you recommend?, I've been using GTX in the buick, and valvoline in the mirage, I can get regular chevron supreme for about 1.15 a quart, cheaper than the others and I've noticed that chevron supreme seems to be a favorite with a lot of people here.
 
Messages
1,874
Location
Ocala, Florida
based on some of the things I've seen and your choices, I'd perfer the GTX over any of them. chevron next. Valvoline imo would never see anything I own. This is just my opinion and based on my over all experiences and research that I have done over the years. This isn't to say that the one is better but those would be my choices with those given oils. Fortunatly, I don't have to rely on those and use Schaeffers. I have not experienced any seal leaks in any of my vehicles that I have switched over but I do use the neutra 131 as a preventative measure when doing this.
 

MustangGT

Thread starter
Messages
233
Location
Pullman WA
Thanks for the help, I've been using GTX in the Buick for a couple of years now, the car has over a hundred thousand miles and still gets good gas mileage 24 MPG in town and 30+ MPG on the highway, it has the 3.3 V6. Buick recommends 10W-30 or 5W-30 (when it's below 60 degrees), on a engine with this much mileage would it make more sense just to stick with the 10W-30 or make the switch to 5W-30 this winter? I live in a cold climate, winter lasts 5 months.
 
Messages
1,874
Location
Ocala, Florida
Mustang, living up in that beautiful country you'd be able to answer that for yourself quite easily. You can do like many and look at the borderline pour point on a tech data sheet or like myself, If you have been running the 10w and in the cold, started your engine, have you ever heard the valves clattering or the engine hard to turn over(not due to a weak battery)? If so, then yes, go to the 5w. Most do not have to but many do it just for good measure. Myself, with the type of oil I use, the 10w30 works fine, even up in your neck of the woods. Bear in mind though, the 5w is designed to be used in colder climates but many 10w's do as well. The big thing is to listen to your engine when you first start it.. That will tell you a great deal on if you are using an incorrect viscosity. If you are concern with the lower temps, it won't hurt to run that. Many do change seasonally from 10w to 5w during the winter.
 

MolaKule

Staff member
Messages
21,600
Location
Iowegia - USA
Mustang, Try the Schaeffer's Supreme 10W30 or 15W40 blends. I have found the 10W30 and 15W40 blends to be good, allaround, near synthetic fluid performance at a good price.
 
Messages
38
Location
PA, USA
From my experience switching to synthetic in vehicles with over 100K miles, I wouldn't do it. My VW scirocco has 170K , burns no oil, the engine is very clean inside but I wouldn't take the risk of putting synthetic in it. You can try those "pseudo" synthetics such as Syntec or Rotella T, and be safe. I personally use heavy duty Diesel oil in my gas car since it's loaded with detergents and drain it at 5K miles. On my VW TDI i use strictly Delvac 1 synthetic for 10K miles. Avoid those "high mileage" marketed oils too, they are just hype. I have been testing the compression in my car every 6 months while using dino oil and is still the same. After the engine dies, it gets rebuilt and gets the synthetic.
 
Messages
951
Location
Loveland, Colorado
About 4 yrs ago I bought a 1990 Saab with 113k miles & a poor history of oil changes. I had not yet completed my conversion to become a True Believer, so it wasn't until 120k that I started using any kind of synthetic. (And 10k mi drain intervals! I found it was more painful for a shorter period of time to convert to both at once. [freaknout] ) The engine's a 2-liter 4-cyl that HAS to go to 3500-3700 rpms to keep up with traffic on the freeway. The car now has 160k on it & has no engine-related or oil-related problems. I did not run any cleaner in it, & it does not have any new-or-larger leaks than it did before. I did switch my initial-run oil filter at 5k, but since have only replaced them during oil changes.
 
Messages
1,908
Location
Fort Worth, TX
While I might not convert a newer, hard-to-work-on vehicle, I have converted several older cars to synthetic without problems: a 350 Chevy with 112,000 miles that I drove to 240,000 before selling; a 26-yr old Chrysler 383 with 78,000 miles that now has 135,000; and a 3/4 ton Suburban 454 at 140,000 miles that now has nearly 200,000 miles pulling an 8000-lb trailer. All were changed over to Mobil One 15w-50. Consumption remained the same, or stabilized, or decreased, respectively. Seal leaks were simply fixed, valve covers that were already leaking on the Chevy and Chrysler. The temperature protection alone was worth it here in hot-as-hell Texas. All had regular changes (3/3) except the Chrysler which sat up for five years with only a couple of changes and a few hundred miles of driving, and then went over a year without a change (9000 miles) prior to my taking possession. The Chevy and Chrysler both required valve stem seal changes prior to switch over. The 350 Chevy is long gone, the Suburban yanks that heavy trailer around in 100-F weather, and the Chrysler is a daily driver. The Sub goes 6000-miles on changes with one conventional filter change at 3000. The Chrysler goes 4-months/4000-miles, sometimes 6/6 with a Mobil One filter. The Chrysler was the only one to receive an engine flush due to low oil pressure at idle; then conventional oil for 500 miles, then cheap synthetic for 2000 miles before a change to Mobil One. Engine was partially disassembled at 100,000 to decarbon heads and valves, R&R timing chain and inspect bottom end. I found no evidence of problems, no sludge anywhere, only a light coat of varnish on cylinder block walls under intake manifold. This was more than 10,000 miles after a severe overheat (lost water pump and drove another 12 miles prior to shutdown). Engine uses approximately one quart per 4000. While regular maintenance is key & experiences differ, synthetic is well worth any small pains when it comes to engine protection.
 
Messages
3,683
Location
Chattanooga, TN
quote:
Originally posted by scirocco16V: Avoid those "high mileage" marketed oils too, they are just hype.
Interesting comment. Are they any different from Delvac 1????????
 

Patman

Staff member
Messages
21,989
Location
Oakville, Ontario
quote:
Originally posted by Spector:
quote:
Originally posted by scirocco16V: Avoid those "high mileage" marketed oils too, they are just hype.
Interesting comment. Are they any different from Delvac 1????????

Are you saying that Delvac 1 is all hype? Seems to me that Delvac 1 has proven itself to be a very good oil, there's no hype there.
 
Messages
3,683
Location
Chattanooga, TN
Not at all. I guess the point I was trying to make was that Delvac 1 is marketed as a long drain interval oil as are the others. the author stated that the others are marketing hype and implied that purchasing them was a waste of funds which I believe is not true as they are marketed not much different then Delvac 1.
 
Messages
2,095
Location
IL
I think by "high mileage", he meant the cars. Maxlife, etc. are not designed for "high-mileage" drains, but high mileages engines.
 
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