I have heard from different people mixed emotions on this. I have been thinking of swapping to Mobil 1 synthetic on my 4runner(95xxxmiles) and my wifes tacoma(145xxx miles). So what's the story should I or not. I have some people that tells me to do it and then others say that if it's never had synthetic don't put it in. What are pros and cons, how could it possibly hurt the engine? By the way I have been using Valvoline Maxlife 5w-30.

 

I don't know about the saying with if it's never had synthetic, then don't put it in, but I have heard that once you go synthetic, you shouldn't go back to regular oil.

That being said, I run Mobil 1 in my truck since the guy I bought it from (a Toyota nut) has always run Mobil 1 in all of his Toyotas and never had a problem. I guess stick with what works.

Rob

 

Just make decision...there is no recourse if you get the "wrong" information off the internet. You will have people tell you they've ran synthetic with no problems and mineral oil with no problems. If you change it every 3k odds are it doesn't really matter.


http://www.dezmo.com/oil03.html
http://www.dezmo.com/gordononoil.html
http://www.dezmo.com/dezonoil.html
http://www.bobistheoilguy.com/

 

Some facts about synthetic oil:
- if you have leaks, synthetic will tend to make them worse
- if your engine is very worn, synthetic will not help much
- if your engine is not worn, synthetic WILL reduce the amount of wear
- synthetic is more expensive
- you may want to consider getting a filter re-locating kit so you could use a larger filter.
- you should be able to extend the OIL changes to 10K, if you change the FILTER every 3-5K (providing it's a bigger filter). This can make up for the extra cost of synth oil.
- it will take several (3-4) oil changes of synthetic to fully "flush" your internals to full synth.

Having said all of this, the move to synth depends on the intent for the vehicle. If you trully intend to keep the vehicle for an additional 100K miles, and if the engine isn't worn (under 100K) currently, then synth may be a good choice.

I have run synthetic oil in all of my vehicles, including my race-cars ('72 Datsun 240z), and will continue to do so.

 

Many threads on this and many different opinions scattered throughout this board. I switched right before 100k to synthetic b/c I don't drive more than 10k miles a year and wanted to do preventative maintenance once a year.

I'm about five months into this and will let you know by the end of the year if I've had any issues. So far, so good.

BTW, I also swapped synthetic into the auto tranny and diffs.

 

I switched my Runner over at 96k when I bought it and no problems but if it had another 100k on it I would've just stuck with dino oil.

 

Thanks everybody! I was just wondering. I've got a few quarts of valvoline left from the case I bought a few months ago. I'll probably use it this time then maybe check into Amsoil, because I got a friend that can get it. he runs it in his ATV.

 

I always run sythetic in my rigs. I switch my current truck over at 150K. No issues. I go so far as to use synthetic grease on u-joints and wheel bearings. They are a far superior product. If you run the larger filter and change it you can got 25K on Amsoil products. Throw a by-pass filter in and your oil will look almost new at 25K. Defenitally better on the engine, and can be cheaper over the life of the rig.

 

[QUOTE=uberhahn]Some facts about synthetic oil:
- if you have leaks, synthetic will tend to make them worse
- you should be able to extend the OIL changes to 10K, if you change the FILTER every 3-5K (providing it's a bigger filter). This can make up for the extra cost of synth oil.
QUOTE]


Hogwash! That whole leak myth is just that; a myth. Don't change the filter between oil changes, that's stupid. Just use a hi capacity premium oil filter (WIX, OEM, etc). And if it takes you a year put 10K miles on your odometer, then don't do a 10K mile oil change interval. Make it 7K or so. You can't have a free lunch. If you don't change your oil for a year, regardless of oil type, you're not maintaining your vehicle properly.

 

I think this is only your opinion. I'm not hear to start a thread war but I've seen oil analysis reports greater than 10k mileage stating that they could have gone longer. Now whether they put on the mileage in one year or over a year is something I'm not certain; but I would trust these reports over your opinion. I do use an Amsoil 25k filter for my 10k mileage interval.

 

[QUOTE=spindleshanks]
Check this page out. It has the recceommend drain intervals for Amsoil.

The oil I use says 25,000 miles or 1 year, whichever comes first.

Synthetic oils are different, they dont break down like conv oils. I only change my oil once a year. And even running a much larger filter I still change it every 5K. A new filter never hurts. When I get my by-pass installed I will change the full flow every 5K, and the by-pass every 10K (which is about 1 year on my P/U).

 

If you don't believe that synthetic is better then stay with what you have. I'm old enough to remember when good oil was good oil and the only argument was which one was the best. They were all good but then they went to hell in a short time.
Now I feel that there is no way you can beat synthetic oils and I believe that Mobile 1 is just as good as Amsoil. Before you switch get a couple quorts of the engine flush they all sell and do it right.
As for how often you should change it I can tell you that I go 8,000- 10,000 miles before I change the oil or the filter. I do change the air filter about every 2,000 miles because that's about how long I go before greasing my Tacoma and I drive in some dusty areas as well as a lot of stream crossings
. Mobile1 has now come out with a 75,000 mile oil and I'm sure Amsoil has one they claim will go longer.
The Idea that you have to change your oil every year is just silly but it's fine if you want to do it. Oil does not break down sitting in an engine anymore than it does sitting on the shelf. What makes me change my schedule of 8,000-10,000 miles is what kind of wheeling I have been doing. If it's off road hot dusty weather then I will change it sooner.Can't say that I have to, Just makes me me feel better.
Been doing it this way for a few years now and have no leaks and it purrs like a kitten. Must be doing something right

 

Sadly, nobody is right all of the time. I'm afraid it's your turn, spindleshanks.

Dino oil will expand oil seals and gaskets, while synthetic oil will not. I has nothing to do with viscosity. I speak from personal experience with my own leaky vehicles, in addition to my profession in the automotive industry.

If your oil is "clean" - low particulate count, while maintaining it's viscosity, changing the filter only is a perfectly viable maintenance method. There are bypass filters on big-rig semi trucks that use bypass filters with entire paper-towel rolls as the filtering element, extending the oil change interval significantly.

A little research goes a long way...

 

Full flow filter, like the long life ones from Amsoil are 15 microns. By-pass are 1 or 2 microns usually. Wear normally starts at 5 microns, so you can see whey by-pass is so great. The By-pass on my dads boat, 3406 Cat (about 900 cu in, and 600hp) is about 9" around and 16" tall, and filters at 1 micron. Even in a diesel which turn oil black from carbon, the oil looks clean after 500 hours.

 

I run Royal Purple and have no problems with it... Been almost a year... and last I checked the oil in the dipstick was light brown...

 

What about acidic build up in the oil (longer than 3 months) because of internal combustion by-products. This seems the be a concern for 4-stroke dirt bikes, or is that apples and oranges when talking about trucks??

David

 

That is the main reason for "time limits" on oil changes, not because the oil breaks down over time. Of course with tighter tolerances on modern engines there are less by-products getting to the oil.

hupptoy

 

Now it's your turn to be wrong, uberhahn!

I have had two vehicles with oil leaks that went away after switching to Mobil1. The leaks slowed down after a couple weeks. And, the leaks were gone after a couple months.

I 've heard similar stories from others.

 

Typically small leakes do contiune to leak, if not grow with synthetic. Not saying this is 100% true, but its due to the viscoticty difference. Usually a leak takes something to block it to stop it, depending on where it is.

Synthetic will not, however, create leaks where they dont exist.

 

i use mobil 1, i love it, longer between oil changes and i j ust feel better about it, mental maybe, who knows