GF-4 Based Oil vs. GF-3 - What is the difference?

Mobil 1 5W-30 meets the standards for ILSAC GF-4 (API Certified - Starburst). I suspect that no change in the formula was necessary to meet the new standard (but don't know for sure).

Mobil Clean 7500 (synthetic blend) and Mobil Clean 5000 (conventional oil) also meet the new standard.

For some reason, Mobil 1 Extended Performance oil does not meet all of the ILSAC GF-4 standards. Could be that it does not meet the stricter fuel economy tests, or has too much phosphorus which can shorten the life of catalytic converters. It does meet the engine wear tests.

Basically all one needs for the current starburst standard (now GF-4) is to meet the current API standard along with its corresponding "Energy Conserving" standard.

I think you'll find as oils are relabelled for API SM, they'll nearly all meet the EC standard and thus GF-4. There might be a few exceptions, including some "European Formula" 0W-30 or 5W-30 oils that are designed to be on the heavy side of 30 weight, and won't meet the energy conserving standard. Pennzoil actually markets two different 5W-30 oils in their "Pennzoil Platinum" series.

You've got that one. They have extra "SuperSyn" which is what Mobil calls a "high viscosity index polyalphaolefin". Basically what it does is serve as a base oil that also increases the viscosity index. I've heard using it also eliminates the need for other VI improvers in weights that previously needed it (or they now need less VI improver). So what you end up with is a slightly thicker oil (closer to the max for the viscosity range) at operating temps, which reduces fuel economy.

ILSAC GF4 is only met by API latest standard energy conserving grades. There is a misapprehension that some European specification oils that meet higher performance standards will somehow meet and [easily exceed] the API standard but somehow fail the 'energy conserving' starburst. In fact it is probable that the only reason that the starburst is not awarded is that the sales volume of these oils would not warrant the accreditation and licensing fees levied. In Europe where these oils are commonplace the starburst and ILSAC standard is not used. Instead the owner is trusted to use appropriate quality and viscosity for his application and to be intelligent enough to know that a thin oil will be more fuel efficient. Effectively any oil with the required API rating and a 'w' rating of 5 or lower and a hot viscosity of 30 or lower would qualify for the starburst if a wad of money changed hands.

Huw

I don't know about the "wad of money" part. According to

thefees are as follows:"6. Licensee agrees to pay to API an annual minimum royaltyfee [eight hundred fifty dollars ($850) for API members; onethousand fifty dollars ($1,050) for non-members] plus$0.0015 per gallon of licensed motor oil after the firstmillion gallons of production. This minimum royalty may berevised annually if deemed necessary by API to cover thecosts of administration and enforcement of the program.Licensee agrees to submit the necessary annual volume ofsales data and the minimum royalty fee to API within thetime frame specified by API. All fees are payable in U.S.dollars."

Seem pretty low to me.

I think you are wrong about the "a 'w' rating of 5 or lower and a hot viscosity of 30 or lower would qualify for the starburst" part. To get the starburst symbol the oil has to show an increase in fuel economy compard to a 5W-30 synthetic reference oil. From

"Oils tested are now compared to an SAE 5W-30 synthetic reference oil instead of the SAE 20W-30 mineral reference oil used under the old program. Engine oils must achieve

1.1% better fuel economy for SAE 5W-30 motor oils and 0.5% better fuel economy for SAE 10W-30 and SAE 10W-40 motor oils."

Regards,

Ed White

There is some confusion here because neither 10w/30 nor 10w/40 would qualify as 'energy conserving' and the 10w/40 would most certainly not achieve better fuel efficiency than the reference 5w/30 in any conditions.

Huw

Valvoline claims their 10W-30 Synthetic Blend meets the Energy Conserving requirements

- "SAE 10w30: Is the leading consumer grade. Exceeds all car, light truck, van or sport utility manufacturer's warranty requirements for the protection of gasoline, and turbocharged engines where an API SL, SJ, or CF oil is recommended. Exceeds European ACEA A1 and all requirements of ILSAC GF-3 for API Gasoline Engine Oils and meets Energy Conserving Standards."

Mobil also claims their drive clean 10W-30 meets the Energy COnserving standards

am sure there are many other 10W-30 oils that meet thisstandard. It seems obvious to me it should not be a problem,this fuel efficiency is measured once the oil is atoperating temperature, and at this point, 10W-30 and 5W-30aren't much different. I looked at the API license list, andmost 10W-30 oils are "energy conserving (seeW-30,the ones with the * can be labeled "energy conserving"). Youare right about the 10W-40. I couldn't find anyoneadvertising an "energy conserving" 10W-40 motor oil and notone in the API list was eligible for the "energy conserving"designation. I did notice one interesting item in looking throught the lists - Ford of the US sells only API "SL" 5W20 Motor Oil. Ford of Canada sells both API "SM" and "SL" motor oil. What gives? Both are claimed to be ILSAC GF-4.

Regards,

Ed White

In my reading, I've heard that the "reference oil" used is a PAO-only base oil. My guess is that it probably doesn't contain much (if any) friction modifiers. I doubt the API sets the requirements such that they can't be met.

It would make sense that the API would change to a synthetic "reference oil" because it would reduce variability compared to the previous mineral reference oils.

Mobil specifically states that their new Mobil 1 Extended Life oils (including 5W-30) do not meet the new GF-4 rating, probably because of the fuel-mileage (they specifically say it does meet the engine wear standards).

The regular Mobil 1 full synthetics, synthetic blends, and conventional oils do meet the new standards.

So it would not surprising that some of the high performance oils, such as required in Mercedes vehicles, may not meet GF-4 rating.

Obviously, this has nothing to do with whether the tests were performed or money changing hands.

GF-4 also has upper limit caps on the phosphorus content as the automakers believe that phosphorus contamination from burning motor oil leads to catalytic convertor failures, and the EPA has recently increased the required emissions systems warranty period to over 100,000 miles.

Phosphorus is part of the common anti-wear additive ZDDP and I suspect that Mobil felt they could not put sufficient ZDDP into their Extended Life Oils for the long drain intervals and also stay under the maximum limits of GF-4.

John