Different Oil Viscosities
- Thread starter DR
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Differing energy policies in the respective markets.
Let's see if I understand this. In America the government penalizes the auto companies if they don't meet fuel milege standards, so the auto companies require thiner oils (and whatever other oil modifications help) be run in their vehicles to get minute increases in fuel mileage during the government testing. These minute (per vehicle) fuel mileage increases, taken across the fleet of all vehicles sold, are significant and reduce the penalties the auto company has to pay.
In Europe the government puts the burden directly on the consumer in the form of exorbitant fuel taxes, which drives the consumer to demand better fuel economy. The auto companies desiring sales, follow the consumer demand. European auto companies recognize that the thinner oils have no practical value for engine life and continue to recommend traditionally thicker weights for the good of the engine. The consumer recognizes this fact too and continues to buy the thicker oils because the thinner oils do not produce a significant fuel mileage increase to make it worth running them.
In Europe the government puts the burden directly on the consumer in the form of exorbitant fuel taxes, which drives the consumer to demand better fuel economy. The auto companies desiring sales, follow the consumer demand. European auto companies recognize that the thinner oils have no practical value for engine life and continue to recommend traditionally thicker weights for the good of the engine. The consumer recognizes this fact too and continues to buy the thicker oils because the thinner oils do not produce a significant fuel mileage increase to make it worth running them.
I don't think 5w30's used in the new BMW's and MB's are thick . They are built on the high side of a 30wt is all .
Rational:
Both the U.S. and Japan mandate fuel economy standards.
Europeans don't, they just tax the bejesus out of petrol and diesel.
So, the lower viscosity recommendations are aimed at increasing fuel mileage (lower viscosity, less drag, higher mileage).
Also, there are places in Europe where cars are driven at much higher speeds than in the U.S. and Japan, such as the autobahn.
Irrational:
The Europeans, IMHO, specify oils which are unnecessarily thick. For example, they seem to have a real love affair with SAE 40 oil. SAE 30 oils work just fine even under heavy load and high heat.
Real men run 40-50 or better. Only a quiche eater would run a 5W-20.
Honda specifies 5w20, but its corporate fleet fuel economy average is well above the government mandated level. So they don't need 5w20 to avoid fines. If 5w20 is "bad" and causes engines to wear prematurely, why would Honda specify it? Why would Honda take a chance on tarnishing their proven track record as one of the most reliable and longest lasting vehicles?
Their CAFE is derived with the use of the 5W-20. The method of calculation takes into account the oil recommended, the resistance of the vehicle to movement through the air, the tire inflation pressure recommended, the whole enchilada.
I believe turbochargers are more common among European cars than Japanese, and rare in American cars. VW demands 5W-40 or 0W-40 for the 1.8T engine, which makes sense to me. At 100C, that polymerized oil still runs thinner than it does at low temperatures.
Nobody has noted that Honda and other Japanese manufuctures specify heavier oils in Japan and Europe for the same cars and engines that recommend 5w-20 here.
http://www.valvoline.com.au is the Australian web site for Valoline oil and has service recommendations. For example, for the 1997-2004 Honda Accord with the 3.0L VTEC engine, they recommend 15w40. The 2003-2004 Ford Focus 2.0L Duratec engine gets 5w30. (Maybe they don't have 5W-20 in Australia.
For the same Honda engine, BP (Castrol) in the U.K recommends their 0W-40.
5W-20 in gasoline engines and 10W-30 in heavy duty diesels is the future for fuel savings in both the U.S. and Europe. The new oils will protect the engines just fine.
Ken
For the same Honda engine, BP (Castrol) in the U.K recommends their 0W-40.
5W-20 in gasoline engines and 10W-30 in heavy duty diesels is the future for fuel savings in both the U.S. and Europe. The new oils will protect the engines just fine.
Ken
Many Mfrs. have retro-spec'd their cars for very light oils, and have no impact on Corporate Average Fuel Economy.
I believe the real reason is that the mfrs have to show that the car buyers actually use xW-20 in their cars, or they will lose credit for the small imporvement in fleet economy that it provides.
The difference is small enough that the average driver would never notice it.
I'm sure they only backspeced the engines to try to prove to the masses that it was a good thing.
Several engines didn't get respeced.
Several engines didn't get respeced.
I recall a Ford article mentioning something like a 0.6% increase in economy using 5w-20 instead of 5w30. In essence, in order to keep selling low mpg trucks and SUVs in the US market the OEMs are doing everything possible to get the corporate mileage up. This includes prescribing 5w-20 in the US market while not doing so in other markets. We in the US are told that we're getting a free lunch; 'increased mileage with no decrease in long term durability'. 5w-20 advocates here restate it another way 'everyone else is dumb because they're not taking advantage of the same protection and better mileage', but are ignoring the fact that it's the OEMs that don't seem to be prescribing 5w-20 elsewhere.
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