I just switched to Shell 5w-40 synthetic and I'm wondering how many miles I have before the next change. I used to change between 3500 and 4000 miles. I use the Toyota Desno filter. My truck has 56k.

 

I use Mobil1 Super Syn. 10W-30 and I still change at around 3500 miles, I figure about 40 bucks every 3500 miles ensures a clean engine so it'll last longer...works with me!

Fink

 

With synthetic, I'd follow the Toyota owners manual. 5000 for severe service and 7500 for normal service. I use Mobil 1 with Toyota filters and go 7500 no problemo. The oil often looks new when I change it even after all those miles.

hope this helps.

 

Mobil 1 here, 15w50 in summer when it's hot (south texas), lighter in winter. Still do every 3000-3500 miles. I like the fram tough-guard filters...they have the valve that prevents drainback and keeps a full filter, even when it's been sitting for days.

My 2 cents :-)

 

5000 here with m1 5w-30

 

Thanks for the replies--I think I will try the 7500 mile change interval and watch it. I went with the 5w-40 becuase it gets really hot here in Mexico.

 

7500 here...Mobil1 5w30

 

5000mi here using Mobile 1 10W-30

 

I can't believe with all the information that has been documented over the years that people still change synthetic oil every 3K-4K miles. The new Mobil 1 is good until at least 10K with a new filter every 5K depending on the brand. It has been tested to death. Amsoil recommends 25K miles on their premium oil and 12K on their filter. I just changed my filter at 5K and the Mobil 1 SS looked like I just put it in and I drive like a bat out of hell. Trust the technology.

 

I can't believe so many people are spending money on Mobil 1 synthetic in 4Runners/pickups. Wow. Whatever makes you sleep better. I ran it in my old car with a cranked up aftermarket turbo for reasons of heat fatigue and the fact that i beat the living crap out of it every time i drove it. But after seeing a 17 yr old toyota run for 250K on the original engine (sold it) with castrol GTX and fram filters its whole life, i'm a believer in toyota reliability and build quality, as well as good ole dino oil. So i go about 5-6k with castrol sytec blend and dealer filters.

 

Synthetic oil seems to be working great. I had a BMW with a service indicator that actually "tests" the oil. It did 15k between changes, with some hard driving sometimes. Merc does the same. I think it is pretty much the standard for all luxury brands these days to use synthetic and getting more than 10k seems to be standard between changes. And the engines last for 100-200k easy on those cars, even the high performance engines which takes a lot more stress than a 4Runner engine.

SO I would recon 10k with synthetic between service with normal running should be just fine.

I am planning to go to synthetic at my 20k service after the engine, tranny and drivetrain had a proper "run in". Probably will do 10k intervals then, currently doing 2500 between oil changes.

My gf's Freelander does 7500 between services with synthetic and the oil looks like new.

 

A friend at the dealer told me that even synthetic oil should be changed at around 5k due to thermal viscocity break down, meaning that the protection that the oil provides is weakened. This is what I was told and I have not seen actual test results on synthetic oils so he might be telling me something he has heard and not researched himself personally, although he is a master mechanic. Food for thought

 

Why wouldn't you believe that people are using Mobil 1 in a Yota? It costs about the same as changing dino every 3K miles. Better oil for about the same cash and fewer oil changes. What an enigma. I have seen several independent tests over the last month or so and they tested the engine oil at different intervals (most were every 3K miles with a filter change) and most of the higher end syn. oils lasted way beyond 5K miles. I haven't paid any attention to info concerning blends. I have heard and received some of the dumbest info standing in a garage over the years so I don't treat mechanics as if they do or say no wrong. They're wrong a lot. I have seen the tests and I have seen the oil.

 

I am running dino oil and replace it with new every 5K. Maybe I ought to change it more often.

 

One thing, coming from an engineer (who's now in med school, ironically) who's worked with and run trials on lots of engines:

One key function of your oil, other than lubrication, is to absorb moisture from the crankcase. Several of the previous posts are correct, that you can change synthetics at intervals MUCH longer than 5k, BUT, the oil can only hold so much moisture. It is mainly the moisture that turns your oil darker with age, not carbon. That's why if you open up an engine that has fairly fresh oil, but hasn't been run in months, the raw CAST IRON block doesn't have any rust inside it. Compare this with your cast iron brake drums or rotors that sit outside for the same period. Even though the synthetics don't breakdown for ALOT longer period, they still have a limited moisture trapping capacity. It's kinda like you've soaked the sponge.

It's still a good idea to change the synthetics at 5k or so, but take this info for what it's worth to you. :-)

 

If your set on running synthetics I'd make my OCIs around the 5-6k mark.
That being said I just changed back to dino and 3-3.5k OCIs. I like changing my oil and take that opportunity to crawl around under there and check things out, lube zerks,etc. Remember clean oil is good oil!

 

The dark color of the oil is not necessarily due to the amount of moisture in it. Most of that moisture will be burned off or vaporized once the engine gets up to normal temperatures and run for a while.

It has a lot to do with the type of fuel the engine is run on. Propane powered vehicles don't darken the oil as much as gas powered vehicles. Diesel engines have very dark oil in short order, and is fairly nasty stuff.

 

I run 5k on M1 dino, I'd probably use CastrolGTX but the M1 cost less and they usually have it.

My Dad had Chevy Suburbans that he put 500k+ on using only regular oil and this was 10 years ago so I think it's OK to use the regular oil cause it has been way improved and if his Chevys ran that hard and long, just the weight he put in them they where way overloaded, and could do that type of mileage then I think where safe.

This whole oil change thing is like the premium gas or not, on 1 end people who should put premium in their cars don't and you got people with 4bangers filling up with premium and then you have people who never change their oil and will run 10-20k before a change on dino and then people buy synthetic and change it every 3k it personel preference

I always wonder if the 1st owners and/or next/previous owners take care of the vehicles just as well, would kinda such the next guy never changes the oil on a vehicle that was highly maintained or your changing the oil every 3k and the engine is shot,

 

Mobil 1 is top of the line oil, no doubt. It's used in high performance engines with high temps and high revs. Believe it or not this is not the life of a (at least my) 4Runner. Perhaps with a supercharger running a good amount of boost I might be more tempted to use it, but I can't reason ever doing that either. As someone else pointed out, it's sorta like using premium when all you need is regular. It's a preference thing. I pay much less than I would be paying with Mobil 1 synthetic, and I see no justification to do otherwise, but to each his own. Even with Mobil1, I don't think i'd ever talk myself into going 2X as far as I would with the current oil i'm using (10-12k miles).

 

AMSOIL founder A.J. Amatuzio coined the phrase "extended drain intervals" back in 1972 with the introduction of AMSOIL 10W-40 Synthetic Motor Oil, formulated for 25,000-mile/one-year drain intervals. Not only was AMSOIL motor oil the first synthetic oil to pass American Petroleum Institute (API) service requirements, AMSOIL INC. was the only motor oil company promoting oil drains beyond 3,000 miles.

Today, motorists are still bombarded with propaganda from the major oil companies promoting 3,000-mile oil changes. However, the industry is slowly but surely coming around. Vehicle manufacturers typically suggest 5,000- to 7,500-mile intervals in their owners manuals, and many manufacturers have also started incorporating oil life monitors into their vehicles, allowing motorists to safely extend drain intervals by monitoring oil life and alerting drivers when the oil needs changing. Competing oil companies have also begun marketing their own synthetics, some claiming service lives extending beyond 3,000 miles.

Lubes-n-Greases Automotive Editor David McFall, once with the American Petroleum Institute recently tackled the issue of extended drain intervals in his March column, criticizing the standard 3,000-mile oil change and referring to the American motor oil market as "shackled."

"In Europe the average engine oil drain interval for current gasoline-fueled cars is about 10,000 miles," explains McFall. "In the United States, indicates the Automotive Oil Change Association, the average drain interval followed by most drivers is somewhat less than 5,000 miles—one-half of Europe's.

"Every year in the United States, this too-short drain interval results in the unneeded production of 300 million to 400 million gallons of engine oil; excess consumer expenditures of around $1.5 billion; and tens of millions of unnecessary oil changes."

Not only are these unnecessary oil changes an expense to consumers, explains McFall, but they have an environmental cost as well. "The added environmental cost of having an average 5,000-mile oil drain interval (instead of 10,000 miles, as in Europe) may be nearly 100 million gallons of engine oil being dumped, untreated, into the U.S. environment annually."

McFall's examination of Mobil 1, Shell and AMSOIL demonstrates the differences among companies who are shackled to the current system and one who isn't.

According to an ExxonMobil spokesperson, "Car owners should follow the oil change intervals specified by the manufacturer. We believe it is inappropriate to recommend drain intervals that may conflict with those set forth by the car manufacturer's specifications."

"Here, in a nutshell," says McFall, "is this observer's take on ExxonMobil's and the oil industry's 'owner's manual' position: It is designed solely to increase motor oil sales." He backs it up by mentioning that Mobil 1 SuperSyn motor oil claims to meet European ACEA A5 and B5-02 specifications, two specifications intended to extend oil drain intervals. "If the oil can be used in Europe for extended drain intervals, why doesn't ExxonMobil notify U.S. consumers of that capability?" asks McFall.

Although Shell Oil Products, owner of Pennzoil-Quaker State, has broken through the shackles enough to offer an API unlicensed oil specially formulated for higher mileage engines, they make no mention of a recommended drain interval, preferring instead to avoid the issue and keep consumers in the dark.

McFall marvels at the success of the independent motor oil company that offers drain intervals up to 11 times longer than the standard interval offered by conventional oils, saying, "Purists can sniff that AMSOIL's data isn't derived from a controlled field study, but the sheer mountain of vehicle miles over three decades, and the absence of any confirmed performance, wear or maintenance issues, speaks volumes."

McFall sums up his column by highlighting the true value of AMSOIL Synthetic Motor Oil, stating the cost may be "two to three times higher than most retail conventional oils but if you can securely count on a 15,000- to 25,000-mile drain interval, it's a flat-out bargain, not to mention providing a clear environmental bonus."

So, what is it that allows AMSOIL motor oils to be used for extended drain intervals, while other oils must be changed significantly sooner? First, the synthetic base stocks with which AMSOIL motor oils are formulated are worlds apart in quality compared with conventional base stocks. The synthetic molecules are uniform in size and shape, resisting the vaporization that boils off the smaller molecules of conventional motor oils and leaves behind a thicker, higher viscosity oil that compromises engine protection. AMSOIL motor oils surpass even the most stringent European volatility standards, providing superior protection for extended drain intervals.