oil
06-28-2007 | 01:21 PM
#26
Rotary Wanker
Joined: Sep 2005
Posts: 413
Likes: 1
From: Washington, DC
I don't disagree with you. Ford classifies the RX-8 as a "light duty" vehicle so, in their estimation, using 5W-20 is perfectly OK. I was only making the point that Mazda technically recomends 5W-30 - it's Ford that makes them use 5W-20 in North America. By the way, I use 5W-20 in my car but I'm still suspicious.
06-28-2007 | 01:52 PM
#30
⎝⏠⏝⏠⎠
Joined: Apr 2004
Posts: 8,625
Likes: 5
From: USA
Question: My owners manual specifies 5w20 oil. Do I really need to use 5w20 oil and why did my 2000 model year vehicle require a 5w30 oil, while the exact same engine in my 2001 model year vehicle requires 5w20 oil?
Answer: No. You do not need to use a 5w20 oil. The only reason 5w20 was specified for your engine is to increase the CAFE (Corporate Average Fuel Economy) reported to the Federal Government. CAFE is the combined average fuel economy of all of a vehicle manufacturer's product line. Minimum CAFE levels are specified by the Federal Government. In order for a vehicle manufacturer to continue selling profitable large trucks and SUV's, which typically have poor fuel mileage, and still meet mandated CAFE requirements, they must also sell smaller cars which have much better fuel economy ratings to offset the poor fuel economy ratings of the larger vehicles.
For model year 2001, the change to 5w20 oil will allow a vehicle manufacturer's overall CAFE to decrease by a very small amount, typically in the tenths of a mile per gallon range. 5w20 oil is a lighter viscosity than a 5w30 oil and therefore has less internal engine frictional losses, or less drag on the crankshaft, pistons and valve-train. This decrease in frictional power loss promotes increased fuel economy. This increased fuel economy is virtually undetectable to the average consumer without the use of specialized engine monitoring and testing equipment when compared to a 5w30, 10w30 or a 0w30 viscosity motor oil.
Question: What are the negative aspects of using a 5w20 oil?
Answer: 5w20 oil has less film and shear strength than a 5w30, 10w30 or a 0w30 motor oil. This can lead to increased engine wear under today's demanding heat and high-stress engine performance conditions.
Question: Is the above true of synthetics as well?
Answer: Yes and no. Depends upon what you're comparing. A 5w20 synthetic oil will likely have less film and shear strength than a synthetic 5w30, 10w30 or 0w30. However, if you compare that same synthetic 5w20 motor oil to a petroleum 5w30, or 10w30, it will likely have better film and shear strength.
Obviously, this means it will certainly have better film and shear strength than a petroleum 5w20 oil. So, if you'd feel more comfortable sticking with the manufacturer recommended 5w20, go with a quality synthetic oil.
Question: Don't I have to use a 5w20 oil to maintain my factory warranty if my manual recommends a 5w20 oil?
Answer: Absolutely not. Vehicle manufacturers recommend using motor oils meeting certain viscosity grades and American Petroleum Institute service requirements. Whether the motor oil is a 5w20, 5w30, 10w30 or 0w30 or even a synthetic vs. a petroleum-based oil will not affect warranty coverage. The manufacturer is required to cover all equipment failures it would normally cover as long as the oil meets API service requirements and specifications and was not the cause of the failure.
In addition, the federally mandated Magnuson - Moss Warranty Improvement Act states that a manufacturer may not require a specific brand of aftermarket product unless it is provided free of charge. If your dealership continues to tell you that you need to use 5w20 oil to maintain your warranty, then ask them to put it in writing. If they indicate you must use a particular brand of oil to maintain your warranty, tell them you expect it to be provided free of charge.
Their position is inaccurate and, in fact, violates existing U.S. legislation. Additionally, if there is ever a question of whether or not a particular oil was the cause of an engine failure make sure to get a sample of the used oil in a bottle, typically 6 oz. minimum. That will provide enough fluid to send oil to 2 independent testing labs for analysis. Remember, being a knowledgeable and informed consumer is your best defense against being taken advantage of by a car dealership service center.
NOTE: If you've purchased an extended warranty, the above may not apply. Extended warranties are not necessarily bound by the same regulations as factory warranties are.
Answer: No. You do not need to use a 5w20 oil. The only reason 5w20 was specified for your engine is to increase the CAFE (Corporate Average Fuel Economy) reported to the Federal Government. CAFE is the combined average fuel economy of all of a vehicle manufacturer's product line. Minimum CAFE levels are specified by the Federal Government. In order for a vehicle manufacturer to continue selling profitable large trucks and SUV's, which typically have poor fuel mileage, and still meet mandated CAFE requirements, they must also sell smaller cars which have much better fuel economy ratings to offset the poor fuel economy ratings of the larger vehicles.
For model year 2001, the change to 5w20 oil will allow a vehicle manufacturer's overall CAFE to decrease by a very small amount, typically in the tenths of a mile per gallon range. 5w20 oil is a lighter viscosity than a 5w30 oil and therefore has less internal engine frictional losses, or less drag on the crankshaft, pistons and valve-train. This decrease in frictional power loss promotes increased fuel economy. This increased fuel economy is virtually undetectable to the average consumer without the use of specialized engine monitoring and testing equipment when compared to a 5w30, 10w30 or a 0w30 viscosity motor oil.
Question: What are the negative aspects of using a 5w20 oil?
Answer: 5w20 oil has less film and shear strength than a 5w30, 10w30 or a 0w30 motor oil. This can lead to increased engine wear under today's demanding heat and high-stress engine performance conditions.
Question: Is the above true of synthetics as well?
Answer: Yes and no. Depends upon what you're comparing. A 5w20 synthetic oil will likely have less film and shear strength than a synthetic 5w30, 10w30 or 0w30. However, if you compare that same synthetic 5w20 motor oil to a petroleum 5w30, or 10w30, it will likely have better film and shear strength.
Obviously, this means it will certainly have better film and shear strength than a petroleum 5w20 oil. So, if you'd feel more comfortable sticking with the manufacturer recommended 5w20, go with a quality synthetic oil.
Question: Don't I have to use a 5w20 oil to maintain my factory warranty if my manual recommends a 5w20 oil?
Answer: Absolutely not. Vehicle manufacturers recommend using motor oils meeting certain viscosity grades and American Petroleum Institute service requirements. Whether the motor oil is a 5w20, 5w30, 10w30 or 0w30 or even a synthetic vs. a petroleum-based oil will not affect warranty coverage. The manufacturer is required to cover all equipment failures it would normally cover as long as the oil meets API service requirements and specifications and was not the cause of the failure.
In addition, the federally mandated Magnuson - Moss Warranty Improvement Act states that a manufacturer may not require a specific brand of aftermarket product unless it is provided free of charge. If your dealership continues to tell you that you need to use 5w20 oil to maintain your warranty, then ask them to put it in writing. If they indicate you must use a particular brand of oil to maintain your warranty, tell them you expect it to be provided free of charge.
Their position is inaccurate and, in fact, violates existing U.S. legislation. Additionally, if there is ever a question of whether or not a particular oil was the cause of an engine failure make sure to get a sample of the used oil in a bottle, typically 6 oz. minimum. That will provide enough fluid to send oil to 2 independent testing labs for analysis. Remember, being a knowledgeable and informed consumer is your best defense against being taken advantage of by a car dealership service center.
NOTE: If you've purchased an extended warranty, the above may not apply. Extended warranties are not necessarily bound by the same regulations as factory warranties are.
06-28-2007 | 06:37 PM
#32
Not so quick......
It's not as simple as thicker/film strength, you may be comparing apples and orangutans....
The 5w30 may be a dino-juice blend , laced with lots of pour-point depressants/polymers to pass the certification tests, after a short time in the engine the polymers could be sheared to pieces, thinning it out or worse, causing sludge build-up.
On the other hand, it is ALMOST impossible to make a 5w20 pass the tests without using substantial amounts of synthetic oil in the mix. The synth is "naturally" a 5w20, without additives - beat it, heat it, slice it, dice it - it will still be roughly 5w20, so the thinning and breakdown products don't enter the equation......
Even Ford's own Motorcraft 5w20 is a synth-mix, you would have look very hard to find one that isn't.
S
The 5w30 may be a dino-juice blend , laced with lots of pour-point depressants/polymers to pass the certification tests, after a short time in the engine the polymers could be sheared to pieces, thinning it out or worse, causing sludge build-up.
On the other hand, it is ALMOST impossible to make a 5w20 pass the tests without using substantial amounts of synthetic oil in the mix. The synth is "naturally" a 5w20, without additives - beat it, heat it, slice it, dice it - it will still be roughly 5w20, so the thinning and breakdown products don't enter the equation......
Even Ford's own Motorcraft 5w20 is a synth-mix, you would have look very hard to find one that isn't.
S
06-28-2007 | 08:39 PM
#34
Just my input, my dealership is constantly warning me about not using 5w30 stating it will ruin the engine, I didnt know you could use it (learn something everyday I guess). Just use 5w20, its recommended, and carry a quart of oil with you, if you drive your 8 for about 1000 miles highway, youll prob have to top off your oil. I made a 300 mile trip, drove 300 miles while there, then on my way back about 10 miles from my house, my low oil light came on, and I had an oil change before I left. So, to review, 5w20, and oil in your trunk at all times, you'll be fine 
06-28-2007 | 09:23 PM
#36
Registered
Joined: May 2006
Posts: 575
Likes: 0
From: Milan, Michigan
5w30 is OK also....
Look at this video... about 4m50s...
http://www.youtube.com/watch?v=lYEpU...elated&search=
Last edited by puch96; 06-28-2007 at 09:30 PM.
06-28-2007 | 10:45 PM
#40
Of course—why didn't I realize it before!! Mazda has been recommending a grade of oil that will ruin all of our engines in 30K miles, so that they can then replace them under warranty. Not to mention alienate tens of thousands of North American buyers, who will never want to own another Mazda again.
Makes perfect business sense.
Makes perfect business sense.
they cant tell if it works in the beginning. but remember it took them 2 something years to *wake up* and *re-adjust* the OMP rate for 5w-20 oil. (the recall)
and North America market has an unusual high amount of engine failures. and we're the only one who has 5w-20 by default.
So, that tells me something.
For Honda, who knows what are the long term effect ? Just gotta wait and see.
Im happy with 5w30, no problems, and I think it will protect better than 5w20. not saying 5w20 will mess anything up. but I think I will stick with what the rest of the world use.
06-29-2007 | 12:19 PM
#41
Grand Chancellor
Joined: Jul 2003
Posts: 2,730
Likes: 58
From: Home of the NIMBYs
06-29-2007 | 01:14 PM
#44
sleddog_racer
Joined: May 2007
Posts: 46
Likes: 0
From: Cambridge, Ontario
I have a 2004 Toyota with 156k on it and have used 5W-20 since new (Manuf. recommended)........engine still runs like new. Yes, it is a piston engine and not a rotary but I don't think it pays to over-think or second guess oil weight recommendations.
06-29-2007 | 01:46 PM
#45
Lubricious
Joined: Oct 2003
Posts: 3,425
Likes: 4
From: SF Bay Area, California
The following is my conclusion from reading the discussions about RX 8's rotary engine failure problems from other RX 8 forums on the Internet and from currently owning a 2005 RX 8. You can form your own conclusions The only thing wrong with Mazda RX 8's sold in the USA is that Mazda USA requires the use of a very thin light weight 5W-20 oil that breaks down and cannot protect the rotary engine and catalytic converter from early failure, because the normally very hot running engine runs very, very hot especially in slow traffic and long drives in warm weather. Every city in the USA has slow traffic jams and warm weather so what good is the RX 8 using this oil in the USA. Every where else in the World (except in the USA) Mazda requires in the RX 8 Owners Manual the use of 5W-30 oil to adequately protect the very same hot running rotary engine that is in RX 8's in the USA. The heavier oil protects the engine and oil seals from failure and prevents oil blow by from ruining the catalytic converter, for over 200,000+ miles, as documented in many forums on the web. For example, printed on Castrol bottles of 5W-20 weight synthetic oil, says "use only in cars used for short trips" and another 5W-20 Castrol bottle of non synthetic oil says "use only if required by the car manufacture". Other wise, Castrol ,who sets the standard for excellent oil, does not recommend the use of 5W-20 oil unless directed to by the car manufacture or for short trips. In addition, Castrol can be objective with out any conflicts of interest about which oil weight not to use to protect an engine, because it does not manufacture cars nor have any vested interests or concerns about meeting EPA miles per gallon requirements to avoid fines. In the USA the RX 8 engines using the very light 5W-20 weight oil last maybe for around 30,000 miles before needing to be rebuilt a number of times before and after expiration of the warranty. This is probably why Mazda now only warrants the car for 3 years or 36,000 miles instead of the prior warranty of 5 years or 50,000 miles. This is also clearly documented in many RX 8 owner web sites. However, in the USA Mazda requires the use of inadequate light weight 5W-20 oil in order for Mazda to meet EPA miles per gallon (MPG) gas consumption requirements. This light weight oil shortens the life of this normally very hot running rotary motor to around 30,000 miles, at the expense of the consumer who needs to keep spending lots of money and time to keep it running. The owners must keep them running because no dealership wants to take the car in on trade or offer a fair amount on trade due to the now widely known problems Mazda has caused to happen to the RX 8 New buyers should consider not buying Mazda RX 8 cars until Mazda permits USA owners to also use non synthetic 5W-30 oil in their rotary engine, without loosing their warranty, as Mazda recommends throughout the rest of the World. Mazda could still put in the USA, RX 8 owners manual, recommendations to use 5W-20 oil to satisfy EPA , but not cancel the warranty of those who wisely choose to use non synthetic 5W-30 oil as recommended by Mazda, thorough out the rest of the World. A class action law suit will straighten out Mazda and increase the life of our cars and make the car worth a proper amount when traded. RX 8 owners in the USA did not buy their RX 8 with full disclosure by the Mazda dealership that the car motor and catalytic would wear out much, much quicker than other cars, due to Mazda oil requirements in the USA nor how Mazda treats the USA RX 8 customer. My Mazda dealership before purchase told me the RX 8 motor would last over 200,000+ miles because it was the nature of rotary engines. With the first oil change though they also told me they would not put 5W-30 weight oil in my RX 8 because according to them it would damage the engine (which is a lie) and would void the warranty, according to Mazda USA. Well it is common knowledge now with the USA Mazda required use of 5W-20 oil that the engine will not last 200,000 miles as advertised and more like it the motor will only last around 30,000 miles before needing to be rebuilt again and again etc. Every RX 8 owner in the USA had better individually or join together to fight the Mazda lies about the weight of oil to use in their RX 8 or their motor's will have a very short life with no one to blame in the long run except for your own lack of sticking up for yourself and what you know is right.
Please, Dear God...........
Last edited by Nubo; 06-29-2007 at 01:51 PM.
06-29-2007 | 02:55 PM
#46
Registered User
Joined: Apr 2007
Posts: 152
Likes: 0
All being said I'd put 5w-30 weight oil in my RX-8 if I was driving it. Everybody else in the world is using it. Why would you want the extra protection? If it didn't void the warranty, I'd use 5w-30 especially if it was used and out warranty.
In a high reving hotter then normal engine the oils going to thin out anyway, why not have the extra protection. The only problem I could see is slower starts in the winter.
Just playing the odds, not base anything on facts across the boards except that most 8s in Europe and Asian aren't having the Engine seal problem and USA is or might be and the common denominator being 5w-20 or 5w-30.
In a high reving hotter then normal engine the oils going to thin out anyway, why not have the extra protection. The only problem I could see is slower starts in the winter.
Just playing the odds, not base anything on facts across the boards except that most 8s in Europe and Asian aren't having the Engine seal problem and USA is or might be and the common denominator being 5w-20 or 5w-30.
06-29-2007 | 03:18 PM
#47
http://www.nhtsa.dot.gov/cars/rules/cafe/overview.htm
The main reason I have read for 5w20 is to help keep the average MPG up for the total vehicles under 8500 lbs gross that a manufacturer sells.
Xw20essentially gets about 2 miles per gallon better than Xw30. The heavier weight can be better but all oils are not created equally so I won't say it is better.
(I was out of breath after reading the lengthy run on sentance post above
)
The main reason I have read for 5w20 is to help keep the average MPG up for the total vehicles under 8500 lbs gross that a manufacturer sells.
Xw20essentially gets about 2 miles per gallon better than Xw30. The heavier weight can be better but all oils are not created equally so I won't say it is better.
(I was out of breath after reading the lengthy run on sentance post above
)
06-29-2007 | 03:34 PM
#48
Registered
Joined: Aug 2003
Posts: 589
Likes: 0
In the USA the RX 8 engines using the very light 5W-20 weight oil last maybe for around 30,000 miles before needing to be rebuilt a number of times before and after expiration of the warranty.>>
Yeah, I've got 10,000 miles on my car and the engine's been rebuilt four times already.
Yeah, I've got 10,000 miles on my car and the engine's been rebuilt four times already.
06-29-2007 | 03:38 PM
#49
Usa....
There is no evidence that "the rest of the world" ISN'T having the same ratio of engine replacements.
You will be a long time finding 5w20 in Brazil or Greece - maybe we get to use the newest/advanced/latest, while the rest of the globe gets instructions to use "whatever"......
....just a thought.
S
You will be a long time finding 5w20 in Brazil or Greece - maybe we get to use the newest/advanced/latest, while the rest of the globe gets instructions to use "whatever"......
....just a thought.
S
06-29-2007 | 03:43 PM
#50
⎝⏠⏝⏠⎠
Joined: Apr 2004
Posts: 8,625
Likes: 5
From: USA
It's CAFE.
The penalty for failing to meet CAFE standards recently increased from $5.00 to $5.50 per tenth of a mile per gallon for each tenth under the target value times the total volume of those vehicles manufactured for a given model year.
Since 1983, manufacturers have paid more than $500 million in civil penalties. Most European manufacturers regularly pay CAFE civil penalties ranging from less than $1 million to more than $20 million annually. Asian and domestic manufacturers have never paid a civil penalty.
For MY 2002, five passenger car fleets including BMW, DaimlerChrysler import, Fiat, Lotus, and Porsche are projected to fail to meet 27.5 mpg passenger car CAFE standard. In addition, two light truck fleets including BMW and Volkswagen will likely fail to meet the light truck CAFE standard of 20.7 mpg. Final Reports for MY 2002 provided by the EPA to NHTSA in mid-calendar year of 2003 may adjust these projections favorably.
Since 1983, manufacturers have paid more than $500 million in civil penalties. Most European manufacturers regularly pay CAFE civil penalties ranging from less than $1 million to more than $20 million annually. Asian and domestic manufacturers have never paid a civil penalty.
For MY 2002, five passenger car fleets including BMW, DaimlerChrysler import, Fiat, Lotus, and Porsche are projected to fail to meet 27.5 mpg passenger car CAFE standard. In addition, two light truck fleets including BMW and Volkswagen will likely fail to meet the light truck CAFE standard of 20.7 mpg. Final Reports for MY 2002 provided by the EPA to NHTSA in mid-calendar year of 2003 may adjust these projections favorably.