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Old Jun 20, 2005 | 02:21 PM
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Default Oil weights and grades

I've seen so many different oil types being used on this site that i am wondering what the benifits of using different oils is. Regular stuff would be 5w30 and 10w30, i guess. But i've heard 5w50, 0w40, and too many others.
Lately i've been getting slightly lower oil pressure than i had before. It is always close to 40 -plus or minus for throttle- right after an oil change, but 1500 or so mile into it it rests at around 20 at idle, probably not a problem.
But thats not what this is about. What i want to know is:

Which oil do you use and why?
What is the difference in all the types of oils people use on this site and is it merely based on outside temp and mods?
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Old Jun 20, 2005 | 02:28 PM
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Owners manual says 5w30 is best, but 10w30 can be used if it won't get very cold. (above freezing I think it says, maybe even lower, it might be down to 0*) Before swapping oil pumps I'd always see 18-20 psi at hot idle, you only need, by rule of thumb, 7-10 psi per 1,000 rpm.

DO A SEARCH. Oil questions come up a lot, esp in the internal engine forum it seems.

The best are full synthetics, obviously. Amsoil, Mobil 1, german/belgium castrol and royal purple. I went with Mobile 1 0w40 and mobile 1 filter recently. (had been using standard valvoline and fram filter. DON'T USE FRAM!) Good old 5w30 should do just fine for average use. As I said, do a search, you'd be amazed how much you can find about oil.

I'd go with Amsoil or Mobil 1. You can get the Mobil 1 a lot of places, such as autozone. It's usually $4.50-$5.50 a quart, depending. For filters Wix, K&N, Mobil 1, etc. BUT NOT FRAM
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Old Jun 20, 2005 | 07:31 PM
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Originally Posted by blkZ28spt
I went with Mobile 1 0w40 and mobile 1 filter recently.
Is there a reason why you chose 0w40 over other types?
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Old Jun 20, 2005 | 07:32 PM
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Originally Posted by spy2520
Is there a reason why you chose 0w40 over other types?
It covers the largest range. I also read some posts by knowledgeable board members (when it comes to oil) and had good things to say about Mobil 1 0w40. It's not the best oil out there, but is more than adequate.
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Old Jun 20, 2005 | 07:48 PM
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i use syn 5w30 and a k&n filter. i like the K7n b/c with the headers and stuff its hard to grip the filter and the k&n has the part so you can use a wrench
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Old Jun 20, 2005 | 10:44 PM
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Right now I'm using Amsoil XL 5w30. It's formulated for longer drain intervals, 7500 miles or 6 months whichever comes first. Since I don't even put 7500 miles on my car a year, the 6 months always comes first for me.

If you have any questions about Amsoil, I'll be glad to answer any questions I can. I'm an independent dealer, and I do have special pricing for fellow LS1TECH members. Just can't post them, so you'd have to PM me.
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Old Jun 20, 2005 | 11:16 PM
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Is there any way to break it down and say 10w30 is for this and 0w40 is for that? I know everything about 5w30 and 10w30 that is said in the manual so those are just examples. I'm actually more interested in knowing what oils people use that are not one of the two that are recommended and why. I know 5w30 is kind of standard, and 10w30 is for slightly warmer climates, but i want to know why (hypothetically) i would want to use 0w40 or any other type people use.

I have an oil change coming up and will definitely be looking into your amsoil prices tranzor_z28.
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Old Jun 20, 2005 | 11:19 PM
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here's why i use mobil 1 0w-40.

First thing is protection of the engine. This is basically covered by the weight of the oil which is repersented by the 40. The higher the number the thicker, and more lubricating the oil is. This is especially good in racing applications, and high temperature applications.

The second is how well the oil flows. This is repersented by the 0w. THE LOWER THE NUMBER THE HIGHER THE VISCOSITY AND FLOW. 0w flows awesome. This means it takes less time for the oil to be circulated thoughout the engine as wells as it takes less time for the oil to get up into the valve train on cold starts. As well a high viscosity is great for cold climates. The bottle states the the oil will still pour at -56. Thats impressive.

All together its a great oil, and I saw a 10-15 psi increase on my oil pressure guage, as well as the engine seems to start and run smoother and quieter.

On a side note the results of my oil analysis, this oil was run for 6000mi, the flash point was off the chart. over 450 degrees. I was impressed with that. Lets see penzoil 10w-30 last that long!

Nathan
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Old Jun 20, 2005 | 11:29 PM
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Thats a perfect reply. Exactly the type of reply i'm looking for, thanks.
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Old Jun 21, 2005 | 12:01 AM
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Originally Posted by natronathon
here's why i use mobil 1 0w-40.

First thing is protection of the engine. This is basically covered by the weight of the oil which is repersented by the 40. The higher the number the thicker, and more lubricating the oil is. This is especially good in racing applications, and high temperature applications.

The second is how well the oil flows. This is repersented by the 0w. THE LOWER THE NUMBER THE HIGHER THE VISCOSITY AND FLOW. 0w flows awesome. This means it takes less time for the oil to be circulated thoughout the engine as wells as it takes less time for the oil to get up into the valve train on cold starts. As well a high viscosity is great for cold climates. The bottle states the the oil will still pour at -56. Thats impressive.

All together its a great oil, and I saw a 10-15 psi increase on my oil pressure guage, as well as the engine seems to start and run smoother and quieter.

On a side note the results of my oil analysis, this oil was run for 6000mi, the flash point was off the chart. over 450 degrees. I was impressed with that. Lets see penzoil 10w-30 last that long!

Nathan

Excellent write-up. The W next to the first number is how the oil acts when it's cold (0 degrees F). The next number is how it acts at 210 degrees F. I run the same oil in my car and picked up some pressure. One more thing about running a synthetic. Synthetic doesn't thin down as much at higher temps, therefore the oil companies don't have to put as much Viscosity Index (VI) improvers in the oil to make it a wider multi-viscosity range (0W-40 for example). However, with a dino oil, they have to put a lot of VI improvers in it to make it a multi-viscosity oil. Then when the oil gets hot for a long period of time, the VI improver additive has a tendency to start evaporating. I used to run a 20W-50 dino oil in one of my cars a while ago and I always changed my oil in the middle of the summer here in Arizona and always picked up oil pressure with fresh oil.
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Old Jun 21, 2005 | 12:02 AM
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I live in the desert, and always use 10w-30 Mobile 1, it flows great at our high temps.
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Old Jun 21, 2005 | 12:25 AM
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Originally Posted by spy2520
Thats a perfect reply. Exactly the type of reply i'm looking for, thanks.
thanks. Its one of like 3 things i know about cars in general...
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Old Jun 21, 2005 | 05:14 AM
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There is tons of great oil info here:

www.bobistheoilguy.com
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Old Jun 21, 2005 | 05:35 AM
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I use Mobil 1 5W-30. Change it every 3 months or 3,000 miles. The 3 months usually comes first.
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Old Jun 21, 2005 | 08:04 AM
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Here is a good link explaining a few things about viscosity and oil, with a few other links to good information: http://auto.howstuffworks.com/question164.htm

By the way, thick things (honey) have a higher viscosity, thin things (water) have a lower viscosity. Oils are measured at a representative operating temperature for purposes of comparison (40°C or 100 °C).

For the first number in 5w-30, the smaller number represents the weight of the oil when cold. In this case the oil has the viscosity and flow like a 5 weight oil when cold. This is important at startup and during cold temperatures to get oil distributed quickly.

The larger number represents how the oil will act at temperature. In this case the oil has the viscosity and flow like a 30 weight oil when hot. This is important during the normal operation of the engine, keeping a strong film of oil on moving parts.

Folks who explore the operating limits of their engines on the high side might want to use a higher weight oil to keep that strong film of oil on moving parts. However, too thick of oil will compromise gas mileage, and too thin of oil will allow more metal to metal contact.

Auto companies will indicate use of a thinner oil (0w-20) to meet fuel mileage requirements and to work with the closer tolerances of modern engines.

Modern oils provide outstanding protection for engines across the spectrum of weights. On dyno day you may want to use 0w-20 to help produce a couple more horsepower, and on racetrack day you may want to use something in a 40w to provide protection at extended high temps and engine abuse.

But for normal driving, 5w-30 or 10w-30 in a sythetic is extremely sufficient.

My .02. Thanks for reading.
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Old Jun 21, 2005 | 11:13 AM
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Originally Posted by Hot02SS
I use Mobil 1 5W-30. Change it every 3 months or 3,000 miles. The 3 months usually comes first.
IMHO, you should really extend that drain interval... using a good synthetic for only 3 months or 3000 miles is like throwing good oil away. Unless its under very harsh conditions (like a mostly track driven vehicle) in which case the use would mandate a unique interval.

For comparison, I go to the track at least twice a month during the season (probably around 12-15 trips to the track in a year, around 60-70 or so 1/4 mile passes) and I change my oil & filter once before race season, and once after... so every 6 months. And my oil comes out looking great even after 6 months of fairly harsh use. In fact I could probably go longer, and just change the filter.

And I'm just using the lowest cost oil Amsoil sells, which is their XL formula. If I used their Severe Service 0w30 or 20w50, I would go with 1 year intervals, change the filter at the 6 month mark.

Point is, synthetic oils are getting better and better, really making the 3 month/3000 mile interval obsolete.
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Old Jun 21, 2005 | 11:36 AM
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Why is there a time limit on oil say the 6 months? I mean it doesnt go bad. Is it a moisture thing?
Dave
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Old Jun 21, 2005 | 11:53 AM
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I think it eventually breaks down to where its viscosity and other properties arent the same anymore.

has anyone noticed the pic in my sig, just added it recently and am very proud!!! lol
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Old Jun 21, 2005 | 12:17 PM
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lookin good!
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Old Jun 21, 2005 | 12:23 PM
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I like that cowl! So how's visability with it? I've been looking at getting a 4" cowl hood, actually...
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