nycgps

iTrader: (1)

A LOT of people will hate you. Some will say *Im sure Mazda know what they're doing. Do you think they will recommend an oil that might compromise their engine in the long run ?*

I said it like a million times, the reason that most of the auto manufactures today went to the lowest weight possible is to increase their CAFE rating. Sad.

robrecht

How much really can it bring up their average corporate fuel economy by using thinner oil? Especially on the RX-8--they only sold 327 of them in the US last month.

nycgps

iTrader: (1)

If u own a multi-million company, you will know what is *every little bit helps*

BMonkey

Yep. Also keep in mind that the industry trend has been towards larger displacement engines, heavier chassis that are safer in crashes, and larger vehicles that have a larger aerodynamic cross section. Even with the advancements in technology to improve efficiency, these trends kinda nullify that.

nycgps

iTrader: (1)

Good thing is that Nissan GT-R is not recommending Bullshit like 5w20. Its going for 0w40. They just cant let bs oil to screw their flagship car up.

swoope

iTrader: (5)

lots of great info here.. thanks paul!!

beers

swoope

iTrader: (5)

cafe = shell game. we all lose..


beers

r0tor

iTrader: (1)

All the wear being seen is on the journal bearings. A journal bearing does not even need antifriction additives in the oil as there is no metal to metal contact. There are industrial lubricants out there used in 50 million dollar turbine power generators that have oil thats composed of basically cheap base stocks and antifoamant additives.

The key to a journal bearings life is flow at start-up, enough pressure and viscocity to keep the shaft floating, clean oil (dirt is what will really wear a journal bearing while in operation), and keeping temps down so the babbit doesn't melt.

Mazmart

iTrader: (12)

All absolutely correct! We have 35 years of rotary evidence, personally, that shows the relation between 'proper viscosities' and improved bearing conditions. This is taking into consideration cold start up, some level of mis-alignment, various foreign particles and by-products of combustion. There are many factors that affect the life of an engine and the bearings in particular, however, we can speak with authority when we make the general statement that a 5W20 is on the terrible end of the scale for this powerplant. Keep in mind that our engine builder had already built over 1000 engines prior to 1980 (Mostly street) and that we've seen numerous championships at several levels of racing as well with more than one class victory at LeMans. In a nutshell, his autopsy skills cannot be easily duplicated nor his experience even by the existing engineers at Mazda corp Japan.

For those of us who like to see 9000 every day, like me, 5W20 is not going to cut it.

The anti-wear additives being reduced is not a problem for bearings. In the piston engines it has taken it's toll on flat tappet valvetrains and caused worry amongst many. We have our own concerns in wear items that get affected by the new standards.

Paul.

xsnipersgox

those tat only "trust" mazda, take a look at the japanese mazda service manual.

http://www.mazda.co.jp/service/owner...x-8/70201.html
使用温度範囲
エンジンオイルは外気温に応じた粘度のものを次の表にもとづき使用してください。


i am sure our cars are vastly different...NOT

mysql

The sticker said my car is only 99% made in Japan. Maybe that 1% is the part that requires 5w20.

Mazmart

iTrader: (12)

mysql, you have mail.

Someone had posted the oil requirements from Mazda in the Deutscheland for the RX8. It recommended up to 20W50 and even synthetics if I'm not mistaken.

Paul.

rotarygod

Just some food for thought on the "every little bit helps" topic. Locomotive manufacturers climb the walls for a few percent improvement in fuel economy. So do truckers. I know some would say that it's because they use lots of fuel and that is absolutely true but it still applies on a smaller scale for regular family types of cars, especially when you factor in their numbers and then look at it from this cumulative viewpoint, which is what CAFE does.

I'm going to throw some numbers out for an example. I will make very general assumptions to keep things simple and hold some things constant for the same reason. The example is valid though.

Let's say your RX-8 averages 18 mpg in your combined total driving life cycle. Let's also say that cycle is 100,000 miles in the life of the vehicle. Let's also say that gas is always going to be $4 a gallon for the entire time. Again, steady numbers for example's sake. Let's say auto manufacturers figured out a way to give you a 3% efficiency increase. Not much but it does add up.

A 3% increase over 18 mpg is roughly another half a mile per gallon or 18.5 mpg (18.54 but let's keep this simple). Now let's use the above numbers.

At 18 mpg for 100,000 miles, your average fuel usage is 5555.56 gallons of fuel.
At 18.5 mpg for 100,000 miles, your average fuel usage is 5405.41 gallons of fuel.
That's basically 150 gallons difference or as your wallet would see it at $4 a gallon, roughly $600 difference. This is what YOU see.

150 gallons per vehicle x the total number of vehicles produced really adds up and this is what CAFE cares about. Remember this is off of a lowly 3% improvement which no one ever seems impressed with.

What if the vehicle in question had 250,000 produced at this higher 3% efficiency level than a previous version? If the above average held true (and I understand it's not quite this simple), that would be 150 gallons saved x 250,000 cars which would be 37,500,000 gallons of fuel saved. Even an average of a 1% improvement in fuel economy (from 18 mpg to 18.18 mpg) would still have added up to 12,500,000 gallons of fuel! Now consider how many cars are being built worldwide and then think about why they do little things that seem meaningless to us as individuals. A little bit does go a long way!!!

Now go plug in the numbers for a fuel efficient car and compare dollar amounts and fuel usage differences!

Mazmart

iTrader: (12)

Not to mention, it's the specific reasoning given by ILSAC and API as to why they are pushing for thinner oils.

Paul.

nycgps

iTrader: (1)

NAW !!!!!!

NEGATIVE !!!!

MAzda Knows their engine ! 5w20 ftw !!!! *sarcasm*

robrecht

Yes, very interesting. But, seriously, how much better fuel economy does the RX-8 really get with 5w20 vs 5w30 or 10w40 or 20w50? Is it a 1/2 mpg? Or much less? And let's multiply that by 327 cars/month instead of 250,000.

nycgps

iTrader: (1)

the total amount is not 327

robrecht

Currently 327/month in the US.

Shoafb

but... if Mazda used the correct oil they would not have had as many engine problems, thus selling loads more cars, while getting worse gas mileage and bringing down the cafe......

mysql

I bet you can't show that the numbers are anywhere near 327 per month on average. So your argument is completely flawed.

It's a decision to use 5w20 across the fleet. Doesn't have to make sense, it just is what they're doing.

rotarygod

They aren't thinking in terms of "327 cars per month". They are thinking in total production of ALL of their cars regardless of model. It's an all or nothing deal. I hate to say it but we are nothing special. Think BIG PICTURE and yes those lowly 327 do in fact add in over time. The last full business year Mazda sold 1.3 MILLION cars!!! My example was only on roughly 20% of that total.

robrecht

But I'm not trying to craft an argument, flawed or not, just trying to ask a question. How much of a mpg increase does 5w20 really provide in our cars? Is is really 1/2 mpg or is it much less? Does anyone know?

robrecht

I know automakers are thinking in terms of all their vehicles sold in the US in order to lower their CAFE fines. I've read somewhere that 5w20 vs 5w30 improves fuel economy by 1% and certainly that can be very significant for all the cars that a manufacturer sells in the US in a year if there average fuel economy is below the mandated CAFE amount. I don't know if that 1% number is accurate, either in general or with specific reference to the Renesis, but that's what I'd like to know. It would also be interesting to know where Mazda (as part of Ford or not?) currently stands with respect to their CAFE fines. All of this is very interesting to me. Truly. But I'm much more interested in maintaining my 'fleet' of 3 cars. The same source that said 5w20 provides 1% better fuel economy on average also said it shortens engine longevity by 30% on average. That's quite a claim. Does anyone know if it's accurate?

rx8convert22

I just wanted to share research I did, and the conclusions I made. I am no expert, but feel I am making an educated decision in switching to Havoline 10W-40. I attached Havoline's data sheet for their SM rated oil.

The thing to note is that their 10W-40 and 20W-50 are both still SM oils but not ILSAC GF-4 oils.

What this seems to means by looking at the test data cart is that the 10W-40 and 20W-50 oils have more Phosphorus and Zinc than the lighter weight oils. These are supposed to help with engine wear.

One negative aspect of these oil though is ash is slightly higher.

I am not sure how to interpret the other numbers. Others feel free to chime in.

My opinion (opinion only) is the 10W-40 and 20W-50 will give me more engine protection at a sacrifice of fuel economy and cat life.

I won't recommend others do the same, but rather urge people to do their own research and come to their own conclusions. I at least hope my opinions are logical and educated.

Also I had been running havoline 5W-30. I just did my oil change to 10W-40. I plan on sending a sample of my 5W-30 for oil analysis and then again with some 10W-40 samples. I hope this analysis may show if there was any wear benefits to the heavier oil.

rotarygod

Manufacturers will give recommendations as to what is in THEIR best interest, not ours as individuals. A measely 1% improvement is nothing for us as individuals. We don't really feel it. In greater numbers it becomes significant. People need to realize that what is written in the owners manual isn't necessarily there because it's in the best interest of longterm vehicle life. That has been weighed by the manufacturer vs the average warranty period, average vehicle life, average time of ownership, and a host of other things. Just because a manufacturer says to use 5W20 does not have to mean it is the best oil for the car. Just because Mazda says no to synthetics (officially. unofficially is another story altogether), does not mean that you can't or shouldn't use them. Manufacturer statements are more political, and financially based for THEM than any other reason including longevity of the vehicles.

It's obvious that the car is capable of hitting mileage that is outside the warranty period. That's all that counts to them. They will sacrifice everything else to get fuel mileage figures up as much as possible as long as the average vehicle will get passed the warranty period. If 5W30 or 10W40 could take the car farther without issue but do it at even the slightest expense of fuel economy, they aren't going to recommend it due to the sheer numbers of vehicles they sell. Don't believe they will tell us what is good for the car. They won't. They'll tell us what they want us to believe and that is based on what is best for them and not us.

Since individuals aren't really affected by such small gains or losses, go ahead and do what's best for YOU and YOUR CAR! Remember that after it's out of warranty, it's your responsibility to pay for it. Rotaries ran 20W50 until the Renesis came out. Don't be scared of a thicker oil. They've always done fine with it. Mazda isn't concerned about your long term engine life but you should be. Don't use what's in their best interest. Use what's in yours.