How often do you change your oil?
07-08-2008, 01:04 AM
#1
Drifting
Thread Starter
How often do you change your oil?
Just wondering how often others change their oil. I just use the cheapest full synthetic I can find, usually quaker state Q power full synthetic.
I also use 5w50 and I'm wondering if that would be bad for my engine as it might be too thin on startup.
I change my oil every 4 months regardless of milliage and I was wondering if that is a waste of money. When I go to school in fall and winter I probably drive 5000 kms every 4 months. I think I"ve done about 15,000 kms in one year.
Also forgot ot mention I use a KN oil filter which is pretty pricey, about 11-12 bucks.
the other day i saw Mobil one in 15w50, one litres each on sale for 7.20 so 6 litres would be about 45 bucks and 12 bucks for an oil filter that's about 60 bucks for an oil change. If I change my oil every 5000 kms or 4 months is it excessive?
I also use 5w50 and I'm wondering if that would be bad for my engine as it might be too thin on startup.
I change my oil every 4 months regardless of milliage and I was wondering if that is a waste of money. When I go to school in fall and winter I probably drive 5000 kms every 4 months. I think I"ve done about 15,000 kms in one year.
Also forgot ot mention I use a KN oil filter which is pretty pricey, about 11-12 bucks.
the other day i saw Mobil one in 15w50, one litres each on sale for 7.20 so 6 litres would be about 45 bucks and 12 bucks for an oil filter that's about 60 bucks for an oil change. If I change my oil every 5000 kms or 4 months is it excessive?
07-08-2008, 01:18 AM
#3
Drifting
Thread Starter
lol I'm in Canada. So even with synthetics like mobil 1 3-4 k miles or 5k kms is when you should change it out?
also is there any real benefit in using a more expensive synthetic like mobil one or redline vs the cheapo synthetics like Quaker state? I don't know if I'm wasting money by paying more for premium oil.
I"m just thinking of buying the mobil one for my next oil change because it's the only synethetic I have found that's 15w50 weight.
what i have in right now is 5w50.
also is there any real benefit in using a more expensive synthetic like mobil one or redline vs the cheapo synthetics like Quaker state? I don't know if I'm wasting money by paying more for premium oil.
I"m just thinking of buying the mobil one for my next oil change because it's the only synethetic I have found that's 15w50 weight.
what i have in right now is 5w50.
07-08-2008, 02:52 AM
#4
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5w50 is probably a little light, except maybe in the dead of winter. Of course, it doesn't get that cold in Vancouver, does it?
15w50 is a good weight, and Mobil 1 is, IMHO, the best oil you can get (I'm sure there will be arguments on that, though).
I usually stick to a schedule of every 4k miles for conventional oil, or every 6k for synthetic. This is assuming no track duty or extreme abuse (occasional abuse is OK, though
).
15w50 is a good weight, and Mobil 1 is, IMHO, the best oil you can get (I'm sure there will be arguments on that, though).
I usually stick to a schedule of every 4k miles for conventional oil, or every 6k for synthetic. This is assuming no track duty or extreme abuse (occasional abuse is OK, though
).
07-08-2008, 03:33 AM
#5
Rennlist Member
I usually do ~ every 6 months...my car doesn't get enough miles to really regularly need oil changes, but I feel better about keeping fresh synthetic in there - I don't really want to have to "reallocate" money for fun projects to something not-fun like replacing spun bearings...
07-08-2008, 04:10 AM
#7
Drifting
Thread Starter
so is 5w50 bad for my engine?
synethetics it's extremely hard to find a 50 weight synthetic that is higher that a 5w winter rating.
the mobil one 15w50 is hard to find also but I found a case. 7.20 / litre sale 8.99 a litre reg price. kind of really pricey.
funny thing is I remember talking to some guy that paid 90 bucks for oil (redline synethetic) for an oil change on his 80's jetta. he said the car has 400,000 kms on it and he only uses the redline.
synethetics it's extremely hard to find a 50 weight synthetic that is higher that a 5w winter rating.
the mobil one 15w50 is hard to find also but I found a case. 7.20 / litre sale 8.99 a litre reg price. kind of really pricey.
funny thing is I remember talking to some guy that paid 90 bucks for oil (redline synethetic) for an oil change on his 80's jetta. he said the car has 400,000 kms on it and he only uses the redline.
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07-08-2008, 11:53 AM
#10
Administrator - "Tyson"
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In theory, no. Once warmed up they are the same.
In theory the 5w will offer better startup lubrication, but it's minimal at best.
Now for the fun answer. 5w-50 is really 5 weight oil with Viscosity Improver's (VI for short) added to make it act like a 50 weight once it reaches 100 degrees celsius.
Same for 15w-50, it's really 15 weight base stock with VI's to make it act like 50 weight at 100 degrees.
The further apart the two numbers, the more VI's have to be added. The more Vi's, the greater chance the oil will break down when stressed.
When this happens the oill will go closer and closer to it's base weight (in this case 5 or 15). This is why most track cars run straight 50 weight oil.
In most street cars that are changed on a regular basis this is not an issue.
I personally would not run a 5w-50 in my Porsche, to wide of a viscosity range. I run 20w-50 in my 928's & 944. I change the oil every spring when they come out of storage. I put less than 5,000 miles on each car. I'm starting to think maybe this is overkill. I might start changing the filter every spring and send the oil off for an evaluation, change it once the lap results say I should.
EDIT - I should have just posted this
From Blackstone Labs:
I cannot remember where I found this:
AND on oil ratings. Why many engine builders are staying away from the new "SM" stamped oil (all gasoline oils on the shelf should be SM). They are sticking with SL & SJ rated oils due to a higher ZDDP content.
More on this subject:
http://www.ttalk.info/Zddp.htm
http://www.sherbournemews.com/oil.pdf
This is why some people are running Turbo Diesel Truck oil that is also rated for gas use (Mobil 1 Delvac 5w-40 for example) or 4-cycle air cooled motorcycle oil. Both of these are available in the "old" standard.
In theory the 5w will offer better startup lubrication, but it's minimal at best.
Now for the fun answer. 5w-50 is really 5 weight oil with Viscosity Improver's (VI for short) added to make it act like a 50 weight once it reaches 100 degrees celsius.
Same for 15w-50, it's really 15 weight base stock with VI's to make it act like 50 weight at 100 degrees.
The further apart the two numbers, the more VI's have to be added. The more Vi's, the greater chance the oil will break down when stressed.
When this happens the oill will go closer and closer to it's base weight (in this case 5 or 15). This is why most track cars run straight 50 weight oil.
In most street cars that are changed on a regular basis this is not an issue.
I personally would not run a 5w-50 in my Porsche, to wide of a viscosity range. I run 20w-50 in my 928's & 944. I change the oil every spring when they come out of storage. I put less than 5,000 miles on each car. I'm starting to think maybe this is overkill. I might start changing the filter every spring and send the oil off for an evaluation, change it once the lap results say I should.
EDIT - I should have just posted this
From Blackstone Labs:
The difference between multi-grades and straight-weight oils is simply the addition of a viscosity improving (VI) additive. The most common grade of automotive oil in use today is the 5W/30, which is a mineral oil refined to the SAE 5 weight viscosity range containing the usual cleaning and anti-wear additives, then blended with a VI additive that should leave it reading in the SAE 30 weight range when at the higher (210F) temperature. The advantage to the multi-weight is, when starting the engine, the multi-viscosity oil has the thickness of an SAE 5 weight, which allows the engine to spin over more easily.
The most common diesel use oil is 15W/40. It is an SAE 15 weight oil with a VI additive that leaves it the thickness of an SAE 40 weight at operating temperature. What makes an oil a diesel-use oil (rather than automotive-use) is the level of additives used. Diesels require heavier levels of dispersant and anti-wear additives. These heavier additive levels are objectionable for automotive engines since they may interfere with the emission controls mandated by the EPA.
The most common diesel use oil is 15W/40. It is an SAE 15 weight oil with a VI additive that leaves it the thickness of an SAE 40 weight at operating temperature. What makes an oil a diesel-use oil (rather than automotive-use) is the level of additives used. Diesels require heavier levels of dispersant and anti-wear additives. These heavier additive levels are objectionable for automotive engines since they may interfere with the emission controls mandated by the EPA.
I cannot remember where I found this:
Viscosity and Wear
Thinner oils have less drag, and therefore less friction and wear. Right? Perhaps in the test engine or engines that experience normal operation. But somewhat thicker oils may offer more protection for more severe operations such as driving through mountains, pulling a boat, dusty conditions, short trips, high rpm, overloading, overheating and overcooling.
Any abrasive particles equal to or larger than the oil film thickness will cause wear. Filters are necessary to keep contaminants small. The other side of the equation is oil film thickness. Thicker oil films can accommodate larger contaminants.
Temperature has a big effect on viscosity and film thickness. As a point of reference, one SAE grade increase in viscosity is necessary to overcome the influence of a 20°F increase in engine temperature. At a given reference point, there is approximately a 20°F. difference between viscosity grades SAE 30, 40 and 50. SAE 20 is somewhat closer to 30 than the other jumps, because SAE 30 must be 30°F higher than SAE 20 to be roughly the equivalent viscosity.
In other words, an SAE 20 at 190°F is about the same kinematic viscosity as an SAE 30 at 220°F, which is about the same viscosity as an SAE 40 at 240°F. This approximation works well in the 190°F to 260°F temperature range. One might be surprised at the slight amount of difference between straight viscosity vs. multiviscosity oils with the same back number (for example, SAE 30, SAE 5W-30, and SAE 10W-30).
If an SAE 50 oil at 260°F is as thin as an SAE 20 oil at 190°F, imagine how thin the oil film becomes when you are using an SAE 5W-20 and your engine overheats. When an engine overheats, the oil film becomes dangerously thin and can rupture.
Ford is bumping up against its CAFE requirements and recommends SAE 5W-20 oil for most of its engines in the United States. It claims SAE 5W-20 is optimal for fuel efficiency and wear.
To determine if SAE 5W-20 oils provide the same level of protection as SAE 5W-30 oils, Dagenham Motors in England, one of the largest Ford dealers in Europe, was consulted. SAE 5W-30 is required for warranty purposes in England, and SAE 5W-20 is not even available. If SAE 5W-20 were better for both fuel economy and wear, why would Ford not recommend it for its same engines in Europe?
Thinner oils have less drag, and therefore less friction and wear. Right? Perhaps in the test engine or engines that experience normal operation. But somewhat thicker oils may offer more protection for more severe operations such as driving through mountains, pulling a boat, dusty conditions, short trips, high rpm, overloading, overheating and overcooling.
Any abrasive particles equal to or larger than the oil film thickness will cause wear. Filters are necessary to keep contaminants small. The other side of the equation is oil film thickness. Thicker oil films can accommodate larger contaminants.
Temperature has a big effect on viscosity and film thickness. As a point of reference, one SAE grade increase in viscosity is necessary to overcome the influence of a 20°F increase in engine temperature. At a given reference point, there is approximately a 20°F. difference between viscosity grades SAE 30, 40 and 50. SAE 20 is somewhat closer to 30 than the other jumps, because SAE 30 must be 30°F higher than SAE 20 to be roughly the equivalent viscosity.
In other words, an SAE 20 at 190°F is about the same kinematic viscosity as an SAE 30 at 220°F, which is about the same viscosity as an SAE 40 at 240°F. This approximation works well in the 190°F to 260°F temperature range. One might be surprised at the slight amount of difference between straight viscosity vs. multiviscosity oils with the same back number (for example, SAE 30, SAE 5W-30, and SAE 10W-30).
If an SAE 50 oil at 260°F is as thin as an SAE 20 oil at 190°F, imagine how thin the oil film becomes when you are using an SAE 5W-20 and your engine overheats. When an engine overheats, the oil film becomes dangerously thin and can rupture.
Ford is bumping up against its CAFE requirements and recommends SAE 5W-20 oil for most of its engines in the United States. It claims SAE 5W-20 is optimal for fuel efficiency and wear.
To determine if SAE 5W-20 oils provide the same level of protection as SAE 5W-30 oils, Dagenham Motors in England, one of the largest Ford dealers in Europe, was consulted. SAE 5W-30 is required for warranty purposes in England, and SAE 5W-20 is not even available. If SAE 5W-20 were better for both fuel economy and wear, why would Ford not recommend it for its same engines in Europe?
More on this subject:
http://www.ttalk.info/Zddp.htm
http://www.sherbournemews.com/oil.pdf
This is why some people are running Turbo Diesel Truck oil that is also rated for gas use (Mobil 1 Delvac 5w-40 for example) or 4-cycle air cooled motorcycle oil. Both of these are available in the "old" standard.
07-08-2008, 12:09 PM
#12
Any oil with a SM energy saving rating lacks ZDDP which is a high pressure additive. The feds figured out they could make the cats on the new cars last 2 years longer if they took it out. Since most new cars today have a roller valve train, its not an issue. Flat lifter cars need the additive because of the friction that occurs between the cam lobe and the lifter. Mobil1 took it out and so did everyone else that wanted to sell a oil with the new SM rating. Red Line and Royal Purple kept the additives in so they still have a SL rating. Check the back of the bottle to look for the API service rating. SL or earlier have the necessary additives for these motors.
07-08-2008, 12:18 PM
#13
Nordschleife Master
I was really surprise at the recommended frequency of oil changes here in the USA after arriving from England. Always changed oil once a year or every 8-12k miles on any car over there. I never heard of a manufacturer recommending an oil change less than 8k miles. IMO I think it's either a myth generated by the likes of Jiffy-Lube etc or a fall back to some of the older US muscle cars.
Still it cannot hurt an engine to do a more frequent oil change, it's just a waste of money (IMO).
Mike
Still it cannot hurt an engine to do a more frequent oil change, it's just a waste of money (IMO).
Mike
07-08-2008, 02:05 PM
#14
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OMG, every 5k km's is total overkill.
I've read that the only real reason you should change your oil is when the corrosion inhibitors are used up, which might happen once every 100k km's or even longer! The reason being that oil only acquired better lubrication properties due to carbon deposits that it absorbs.
It's not entirely far fetched since graphite (which is a certain form of carbon) is an excellent dry lubricant (for those who speak dutch: http://www.niveauplus.nl/kwaliteitsc..._peilstok_chip and http://www.niveauplus.nl/uploads/dow...che_uitleg.pdf).
Short summary:
Old diesels are so damn reliable because of hte nasty combustion: after an oil change it only takes a few 100 miles for the oil to accumulate lots of carbon particles. Gasoline engines take thousands of miles to accumulate this, at which time most of you are already changing the oil.
As a good dry lubricant the carbon aids in starting conditions where the oil has run out of the bearings, minimizing wear. Without the carbon you have more steel-steel contact.
They sell a highly corrosive strip that you solder to your dipstick. When the strip corrodes the corrosion inhibitors are nearly gone meaning your engine may start to corrode. At that time it's time to change the oil.
The author of the site himself has driven his car over 300k km's (nearly 200k miles) on the SAME oil, and not even a filter change. He only topped it up when necessary. The author actually used to work for an oil company and claims oilchange intervals are simply a hoax setup by the companies to boost revenue.
I'm actually inclined to give it a try.
O BTW: current oil changes here are maybe once a year. We rarely make enough miles, but 10k km's a year is within the realm of feasability.
I've read that the only real reason you should change your oil is when the corrosion inhibitors are used up, which might happen once every 100k km's or even longer! The reason being that oil only acquired better lubrication properties due to carbon deposits that it absorbs.
It's not entirely far fetched since graphite (which is a certain form of carbon) is an excellent dry lubricant (for those who speak dutch: http://www.niveauplus.nl/kwaliteitsc..._peilstok_chip and http://www.niveauplus.nl/uploads/dow...che_uitleg.pdf).
Short summary:
Old diesels are so damn reliable because of hte nasty combustion: after an oil change it only takes a few 100 miles for the oil to accumulate lots of carbon particles. Gasoline engines take thousands of miles to accumulate this, at which time most of you are already changing the oil.
As a good dry lubricant the carbon aids in starting conditions where the oil has run out of the bearings, minimizing wear. Without the carbon you have more steel-steel contact.
They sell a highly corrosive strip that you solder to your dipstick. When the strip corrodes the corrosion inhibitors are nearly gone meaning your engine may start to corrode. At that time it's time to change the oil.
The author of the site himself has driven his car over 300k km's (nearly 200k miles) on the SAME oil, and not even a filter change. He only topped it up when necessary. The author actually used to work for an oil company and claims oilchange intervals are simply a hoax setup by the companies to boost revenue.
I'm actually inclined to give it a try.
O BTW: current oil changes here are maybe once a year. We rarely make enough miles, but 10k km's a year is within the realm of feasability.
07-08-2008, 02:07 PM
#15
Nordschleife Master
When i still had my '87 n/a i was running Castrol GTX dino oil, 20w50 in the summer and 10w40 in the winter. I would change it every 3500 miles roughly.
My '88 951 gets Mobil1 15w50, only because thats what its always been getting and i havent bothered to switch brands yet. Ill probably go with Castrol Syntec for the next change. I usually change it every 4500 miles or if i do more than a handful of DE's or Auto-x's ill change it out a little earlier. I dont bother switching oil weights during the winter because im to lazy
.
My '88 951 gets Mobil1 15w50, only because thats what its always been getting and i havent bothered to switch brands yet. Ill probably go with Castrol Syntec for the next change. I usually change it every 4500 miles or if i do more than a handful of DE's or Auto-x's ill change it out a little earlier. I dont bother switching oil weights during the winter because im to lazy
.