# synthetic oil?



## NateHanson (Apr 15, 2007)

My 06 Tundra specifies synthetic oil, and 5,000 mile service intervals. I'm suprised your Taco isn't the same??


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## econdave (Apr 7, 2006)

Until recently I have brought my truck to the dealer for oil changes. Its a pain because the dealer is far from my house and you have to wait a few hours just to get a oil change. 

I hear there is synthetic oil that would allow you to go 7,500 miles between oil changes.


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## slickshift (Aug 25, 2005)

The increased miles in between oil changes, if any, due to synth oil, will be directly related to the engine and how it is driven

I have had four bangers that were "ideally" driven (warmed up in town-decent highway distance commute-no "city" harsh driving conditions) that after 8000 miles the synth looked better than the synth in the big eight cylinder with the 10-minute cold engine commute did at 2000

I suspect at 100 miles a day and with only 20K on the odo, you would be an idea candidate for synth


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## econdave (Apr 7, 2006)

so in your opinion whats the best synthetic oil on the market?


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## slickshift (Aug 25, 2005)

IMO it doesn't matter too much
But-
It has to be a full synth...none of those "blends" 
The oil is only as good as it's weakest link, so those "blends" are just to sell to people that don't want to spend the cash on full synth, but want to feel they are treating their engines better than regular oil
It just separates more cash from the consumer, doesn't really help the engine

And it should be the viscosity/weight that is recommended, or works better, for your engine
I say this because the different brands come in different weights, and not all are good for every engine
Using the two examples above:
The little Japanese four cylinder highway engine did great on the Castrol Syntec (5w-50)
The big old 302 drank that stuff like keg beer at a frat party
The juice was just too "slick" for the large tolerances of the larger, older American eight
However, Mobil 1, available in 10w-30 worked fine in that one

IMO it's best to find an oil in the factory recommended viscosity and then go from there (if need be)


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## econdave (Apr 7, 2006)

so you say I should contact my dealer and ask them what synthetic oil I should use and what viscosity? I thank you for all your help and knowledge in this matter.


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## NothingsLevel (Aug 27, 2006)

The dealer will just tell you to come in and have them do the oil changes with whatever they use.

Use the oil viscosity your owner's manual says to use. Can't go wrong with Mobil 1 IMO.


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## slickshift (Aug 25, 2005)

NothingsLevel said:


> Use the oil viscosity your owner's manual says to use.


That's what I was getting at
If the owner's manual say use a 5w-50, and Castrol has a 5w-50, but Mobil 1 has a 10w-30 and a 10w-40, use the Castrol
If the manual says use a 10w-40, and Castrol only has a 5w-50, use Mobil 1's 10w-40
Amsoil and Royal Purple also have good synthetic products


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## saltydevildog (Dec 24, 2007)

I only run mobile 1 (pure synthetic), and change every 10 thousand, with K&N filters. The filters have a 1 inch nut on them and they are great (10.00 on amazon) I had 170 thou on last blazer, (traded to 07 grand caravan) and still going strong at 130 thou on 98 expedition. The oil looks great after 10 thou.


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## UBoiler (Nov 7, 2007)

So I had a Amsoil sales rep at their product booth at the MN state fair tell me their synthetic oil shows no breakdown of viscosity at 25,000 miles. I said that's nice but what about all the debris and contaminants the oil picks up? He said the Amsoil oil filters need to replaced at 12,500.

I'm skeptical of most things so I haven't taken this guy's word; however I have over 350,000 miles on my 02 Silverado 1500 using the lowest priced 100% synthetic motor oil I can find and changing oil at 10,000 miles.
This model also gave me over 260,000 miles on my first set of front pads so IMO Chev did A VERY FINE JOB OF OVER_DESIGNING and I appreciate it. I had a stickiing rear pad so I didn't get such sensational results with my rear originals but the replacements are doing great!

If anyone has any info on my Amsoil tale or similar surprising luck with 02 Chev brake pad life I'd enjoy hearing about it. Thanks Cliff


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## jerryh3 (Dec 10, 2007)

I run amsoil in both my Maxima and CR-V with 10K change intervals.


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## jren (Jan 2, 2008)

we use amsoil in our race motorcycles. prior to switching I'd do a complete rebuild twice a year. I switched because a customer brought in a motor and it looked brand new. I asked him why he sent a new motor to me. He told me it had 13 nationals on it. so i tried it out. I've extended my full rebuilds to a full year and increased topend life by 2X.

So I cannot speak for the auto motor oils but I would speak highly of their products in general.


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## slickshift (Aug 25, 2005)

UBoiler said:


> ...at 25,000 miles....what about all the debris and contaminants the oil picks up? ....filters need to replaced at 12,500.


Basically...yup
Regardless of how well the oil itself is viscosity-wise, part of it's job is to flush out contaminants, which develop in any engine with any oil

Even if the oil's viscosity is still good at 10K, the filter could be suffering

For that reason extended change intervals reach a point of diminishing returns

Even if the oil still is tests good viscosity-wise, if you are under there changing a filter @ 10/12K, IMO might as well change the oil also


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## jren (Jan 2, 2008)

I guess I sorta disagree. when you run 15quarts of oil like I do the difference between changing a filter and the oil is a big diff $$$wise. in a under 4 quart car I'd tend to agree though.


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## Den69RS96 (Mar 2, 2007)

The oils longetivity has lot to do with the additives used. Synthetics come from crude, they just reshape the molecules and make them more uniform in size where reg dino oil has molecules of different sizes. I use either Mobil One, Royal Purple or Amsoil. Amsoil is hard to find so i mainly use RP, however if its not on sale when I need it, I use mobil one since its a little cheaper. I drive 110 miles a day like EcoDave. I switched to synthetic oil because I got tired of changing my oil every month. I mainly use royal purple and change my oil every 7500-8000 miles. The speed shop I go to swears by it. Bearings look brand new after a full race season. RP claims the oil is fine for 12-15000 miles but requires oil filter changes every 3000 miles. I just cut the difference and do it once at 7500. I just turned 114000 miles and my car runs just like it did new. The royal purple allows it to start easier in the cold temps, runs cooler in the summer, and I picked up 1.4 mpg as well.


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## robtspcr (Feb 10, 2008)

*Synthetic Oil*

You might want to try a Blended Oil of Petro/Sythe. Pennzoil has a good one; not as pricey as full Syn. (There are others) 
3000 mile changes are good if you drive alot of city stop and go for short mileage. (The engine never reachs full operation temp for sufficient time) If you drive hiway or sustained speeds for long periods of time the engine temp cooks off alot of bad stuff and moister. This alone can stretch your oil life up to maybe 4000. I drive Hiway trips of 200 miles every monday and friday; thus about 80% of my mileage. I use the Blended oil and change on a 5000 basis, never had a problem. Now at 157,000 plus on 98 GM PU with 5.7 and she still runs great. Stay with recommended Viscosity.


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## Maintenance 6 (Feb 26, 2008)

What you could do is pour in the synthetic and change it out at the normal interval. When you change it, send a sample to Blackstone Labs in Indiana. For $20.00, they'll analyze it and send you a report. It'll tell you how the oil is performing, viscosity breakdown, additive breakdown and a comparison with other vehicles like yours. They'll even tell you what parts are wearing in your engine from the types and quantities of metals in the oil. I sent in a sample from my Ford powerstroke at 6000 mile oil change and they said that it was what would be expected at 4700 miles. You might find that you can run your oil for a long time if you are highway driving. The amount of suspended dirt in the oil will also tell you if the filter is doing it's job. Potentially you could have a really good oil thats failing because of a really crappy filter, or an oil that's very clean but isn't doing it's job anymore.
http://www.blackstone-labs.com/
I know this almost sounds like an endorsement, but I don't have any connection. We started sending oil samples in from emergency generators that were geting old and they could tell us what to expect as far as repairs. When we did tear downs and inspections, it was pretty much as they said.


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## Tommy Plumb (Oct 7, 2006)

If you're doing all highway driving you can go 4500 miles on dyno oil without a problem. Synthetic should go twice that without a problem. I'd change the filter at 4500 though.
I do all short distance driving as my commute is less than a mile and most of the places I need to go aren't much further. My vehicle rarely sees the highway so I run synthetic, change the filter at 3k miles then do an oil/filter change at 6k. I probably could go even further.

As far as filters are concerned don't cheap out and buy Fram, Purolator, etc or any of that garbage. Yes, Fram has lousy oil filters. On the other side of the coin it's a waste to go buy a $10 Mobile 1 or K&N filter, they don't do anything special. My favorite is WIX or NAPA brand which is re-labled WIX. There is a webpage around where a guy cut open a bunch of oil filters and wrote about what he found, excellent info if you can find it.


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## NothingsLevel (Aug 27, 2006)

Marlin said:


> I do all short distance driving as my commute is less than a mile and most of the places I need to go aren't much further.


You could save a *ton* of money if you skipped driving altogether on your commute and just walked.


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## Leah Frances (Jan 13, 2008)

Blackstone Laboratories will test your used engine oil and provide a detailed analysis and recommendations about oil and change intervals. They have a good reputation in the car enthusiast world. After getting our cars tested (it was @ $20) we drastically extended our change intervals so buying synthetic isn't such a hit to the pocketbook.

You choice of oil can depend on your application. My 1986 Volvo has 400,000 miles on it, and has synthetic in it since Day One. My 1994 RX-7 has a rotary and has to run standard oil. We run synthetic in our 2004 Subaru. We've tested them all more than once.

As for brands - we buy Castrol GTX for standard oil. For synthetics we buy whatever's cheaper: mobile 1 or syntec - but NEVER blends. 

Oh, and try reading your owner's manual - some manufacturers will make specific recommendations about oils.


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