# Castrol Synthec or Mobil 1?



## NYH1 (Apr 13, 2008)

I'm going to switch over to synthetic oil at my next oil change. I want to go with a brand of oil that I can buy locally. That's pretty much Castrol Syntec or Mobil 1. Is there any difference between the two? Is one better then the other? Thanks.


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## chowdozer (Apr 13, 2008)

I think Mobil is easier to find. I like that Mobil comes in a gallon jug. I buy at WalMart. The only thing I buy there.


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## grandpatractor (Apr 13, 2008)

I use mobil 1. I think they have a larger variety of viscosities also.


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## omegajim (Apr 13, 2008)

either.

synthetic oil is all made to such a high standard I don't think it's possible to make a bad choice.

The only bad choice you can make is paying too much.

I also post on a bike thread, and over there they recommend rotella.

But you can't go wrong with synthetic, anything with a namebrand on it.


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## wildbio (Apr 13, 2008)

I pretty much used only the Castrol syntec in my last truck - a Toyota. Got 230,000 miles out of it before I sold it....it still wasn't burning any oil.
In my Dodge I've been using both Mobil 1 and Castrol Syntec. The Mobil usually costs a little more. I'm guessing it's 6 or half a dozen.


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## XJWoody (Apr 14, 2008)

I'd agree that between Mobil 1 and Syntec it's a draw... I'd also pick Mobil for the availabiliy but either is good stuff.

One thing I'd do (maybe passing on a wives-tale?) is after switching to synthetic, for the first change interval or two... swap a fresh filter on at 1000 mi, 2000mi, then drain + new filter at 3000. The second interval, maybe a filter at 1500, and 3000, drain & change at 4500. After that, a filter at 2250 and a change at 4500... I don't think I'd go much beyond 4500 on any oil... but that's just me.

The "wives-tale" being the synthetic oil's detergent properties will "shock & awe" a bunch of sludge loose in it's first couple visits. I guess it depends on how nasty the motor was to begin with... Ideally one would switch over to synthetic oil after the engine has just broken in (5000-7500 or so with 2-3 changes of dino), and sludge buildup wouldn't ever be a real issue.

FWIW I use RotellaT synth 5w40 in my bike, and Dino Castrol GTX in everything else, all at 3000 mile drain & change filter intervals.


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## NYH1 (Apr 19, 2008)

XJWoody said:


> I'd agree that between Mobil 1 and Syntec it's a draw... I'd also pick Mobil for the availabiliy but either is good stuff.
> 
> One thing I'd do (maybe passing on a wives-tale?) is after switching to synthetic, for the first change interval or two... swap a fresh filter on at 1000 mi, 2000mi, then drain + new filter at 3000. The second interval, maybe a filter at 1500, and 3000, drain & change at 4500. After that, a filter at 2250 and a change at 4500... I don't think I'd go much beyond 4500 on any oil... but that's just me.
> 
> ...


I only have 9,000 miles on my truck now.


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## NYH1 (Apr 19, 2008)

I bought Mobil 1 5W-20 oil and a Mobil 1 filter M1-204. My son (6 years old) and I are going to change it tomorrow!


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## cjk (Apr 20, 2008)

http://neptune.spacebears.com/cars/stories/mobil1.html

Heres some reading for ya.


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## omegajim (Apr 20, 2008)

I'm trying to remember what I saw rotella in a 4 qt jug for; something like $20.

About as cheap as synthetic is going to get.

Look around for the 4 quart jug; sometimes it's cheaper, sometimes it's not.


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## gremlin (Apr 20, 2008)

rotella is great oil. i use castrol in the drag car no problems ever


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## glenn31792 (Apr 24, 2008)

If it says Off Road, Racing or is aimed at diesel trucks its higher in ZDDP.
I think the Rotella Synth says Heavy Duty , Think its higher in zddp too.


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## NYH1 (May 3, 2008)

I'm going to go with Amsoil products from now on. They have a wide variety of synthetic oils as well as filters. I bought one of their Ea Air Filters and some Saber (ATP) 2 cycle oil the other day. I'm going to change the gear oil in my front and rear differentials next. I won't be able to buy it locally. It's not that big of a deal though. I order most of my ammo, might as well order my car/truck care products too.


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## Nitroman (May 5, 2008)

I run Amsoil synthetic in the engine, transmission, transfer case, differentials, and power steering pump.


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## Cerran (May 5, 2008)

I'm using Mobil one on the Wife's CRV as that is what is recommended by Honda and until the warranty is up I'll likely stay that way. As has been mentioned though whatever you can find at a good price when it comes to synthetics is a good way to go.


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## omegajim (May 5, 2008)

so what interval does honda recommend for changing said synthetic oil?


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## cjk (May 6, 2008)

Our 06 Civic has an indicator for oil life. At 8000 miles its at 15% and I change it then using regular Mobil 5w20.


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## omegajim (May 8, 2008)

8,000 is a good number; keeping in mind sooner or later the oil filter will get saturated.

I always thought one of the neatest things ever invented (but not often implemented) was a gauge monitoring the air filter.

This air filter monitor gizmo was on a tractor and pointed to green when the filter was good and moved towards red as filter got dirty.

If they could only put something like that on a car's oil.


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## cjk (May 9, 2008)

After rechecking my records, it is 7000 miles, NOT 8000. Sorry. 

The air restriction indicator you mention is used on most diesel engines. I wonder if it could be used on a gas engine. No more guessing if it needs changing. 

I have a 10 year old (400 hours)tractor with the original air filter and the indicator says the filter is still good.


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## omegajim (May 11, 2008)

that doesn't surprise me; depending on what you're doing, I would imagine the air filter could easily exceed 500 hours.

Although I saw the most amazing thing once, a guy I know who is a contractor, noticed his truck was running funny.

Somehow he deduces the air filter could be dirty; it was right out of the movies, I was amazed how much dirt was in between all the baffles. It had to exceed a cupful of dust.

and lastly, my uncle bought a tractor last year and the oil change interval is 500 hours. I think that's pushing it.


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## Freakingstang (May 11, 2008)

been running mobil 1 in my 99 Z-71 since 03. It has over 200+K miles now and still runs strong. 5000K to 6 max to the oil changes I run it in just about everything.


In one of my mustangs, I got about .2 tenths quicker et's out of mobile 1 synthetic over valvoline durablend


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