I was wondering if you can change to synthetic oil in older cars with no problems? I have an 89 with 72k and a 91 with 85k, can I use synthetic, and if so, any recommendations?

 

my recommendation is to not bother.

save the difference in $$ for beer, that'll have a value-added impact.

 

Yes you can use synthetic but you won't see any beifit except maybe longer intervals between oil changes

 

You can use whatever oil you wish you to use, and for the internals it will be better.

However, if you have any leaks now, they will get worse with synthetic. It has detergent packages that eat away gunk that has been sitting/building around seals and gaskets, this can cause leaks to form or get worse.

I had one at the rear main seal, and eventually had to replace it.

 

Totally unnecessary. You could even exacerbate an existing leak. Valvoline and others make dino oils for older high milage cars that actually help with seal longevity. You might look at one of those. I think the Valvoline is called 75,000 +.

 

Thanks everyone, I use the high mileage oil in my F150, 125k and going strong so I think I will just go with a high mileage vs the synthetic.

BD2626

 

 

I have read this on some threads and been told that it is kind of a myth.
I really have not tried to switch to synthetic but planned to use Mobil one.

I still have a doubt:
If I use a Synthetic oil of lets say 5-40 it is supposed to act exactly as a normal 5-40, except for its durability.
But, is there a difference in friction on the engine? Would a synthetic make an engine run cooler due to less friction / drag?
Or should it be exactly the same?

Maybe this will be the dumbest questions but I just need to get the facts straight.

 

Sold?

 

I started using full synthetic motor oil at 96k miles; now, at 176k miles, there are still no leaks...

 

I started using mobil 1 at 68000 miles-now there are some slight leaks at 75000 miles

 

I sorta wondered the same thing. I usually change my own oil and I noticed in winter new oil flows like molasses. I switched to synthetic using the same weight oil and it flowed like water. Since I park my truck outside it gets really cold so I wanted the oil to flow better at start up. Not sure why the same weight flows so different at cold temps??

 

The engine oil in my car gets pretty hot, max so far 210 degrees, I switched over to Mobil one for that reason. No leaks yet but only 1500 miles.

 

I bought my car with 110,000 miles on it. I immediately made the switch to Mobil 1 5/W30. I use a quart between 5k mile changes. I saw a slight but repeatable rise in gas mileage and no extra leaks. Mobil also makes a synthetic for high mileage cars now. I have 122k on the car and still use the Mobil but will be switching to Amsoil at my next change.

 

I bought a 96 with 110K miles that I decided to go through from one end to the other for in-depth hands-on C4 experience. Previous owner said oil was changed at 3000 intervals and was always Mobil1. The car had oil leaks all over the place and everything was coated in oily dirt so I stripped everything out of the engine compartment down to just a block with heads. What got my attention was how clean and new looking it was inside, I mean not even a brown film, just shiny parts. I dropped the oil pump to replace the plastic shaft coupling sleeve and decided to take a look inside while it was off to see if it was worn since I was ordering a timing chain anyway and there was no wear; it looked like a new pump inside. I then started thinking there is no way this could be the original engine but when I wiped the grime off the bellhousing pad the car's serial number was there. It appears to me the engine has never been out of the car and the head gaskets appear to be the originals. The only previous work I can find is the intake gaskets had been changed (sloppy job, still leaking, probably worse), it had a replacement waterpump, the Opti has been apart (probably for cleaning, but it was the original) and the damper hub had been off at some time (Opti removal). Three things came out of this for me:

1) Mobil1 is pretty good oil
2) Just because you have someone attempt to fix your oil leaks does not mean they will take their time to do the job correctly.
3) High miles cars will probably have grooves worn in the damper hub and water pump drive shaft and these will need to be corrected if your goal is a clean dry engine.

 

i have alsways used amsoil, and acheived very good service from it......even switching at high miles...i never have noticed any leaks. and i switched as well to amsoil....theirs series 2000 is a very good oil.

 

Thanks for the info

 

Here we go!!! HAHAHA!! Just remember the beer gets poured down your filler neck, not into the engine!!

Hot Rod, lets get a few tallies in before lunch mate