I would like to hear everyone's thoughts on this, i asked my local dealer today about using a 0w-30 in my Jeep and they said that Warranty Dept would buck if they found i was using a zero weight oil. So then i turn to the parts dept and asked for oil for a 2007 JK Wrangler and the bloke plonks Penrite 0w-40 on the counter which prompted a bit on research on the net and i came up with this.

Quoted http://www.smartsynthetics.com/articles/5w20oil.htm




Do I really need to use 5W-20 or 0W-20 oil? Truth, NO!
Read on for technical facts regarding the use of 5W-20 or 0W-20 motor oil.

Ford, Honda and Daimler- Chrysler specify 5W-20 or 0W-20 motor oil for most gas engine powered cars and light trucks. Is 5W20/0W-20 oil really necessary?

Here are the technical facts behind 5W-20 and 0W-20 oil specs:

Question: My owners manual specifies 5W-20 or 0W-20 oil. Do I really need to use 5W-20 or 0W-20 oil and why did my 2000 model year vehicle require a 5W-30 oil, while the exact same engine in my 2001, 2002 and newer engines "requires" a 5W-20 or 0W-20 oil?

Answer: NO! You do not need to use a 5W-20 or 0W-20 oil. Do not let your dealer scare you by telling you that you have to use 5W-20 oil for your warranty. That is a tactic that some dealerships use to scare customers. Once you know the facts and the Federal Magnusson Moss Act law, you will be much better informed to protect your rights and use the type of fluids you want to use.

The main reason 5W-20 or 0W-20 oil 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 manufacturers 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 ratings, as compared to smaller cars, and still meet mandated CAFE requirements, they must also sell enough of the 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 a 5W-20 oil will allow Honda and Ford's overall CAFE to increase by a very small amount, typically in the tenths of a mile per gallon range. 5W-20 oil is a lighter viscosity than a 5W-30 oil and therefore has less internal engine frictional losses, or less drag on the crankshaft, pistons and valvetrain, which in turn promotes increased fuel economy. This increased fuel economy is virtually undetectable to the average motorist without the use of specialized engine monitoring and testing equipment under strictly controlled test track driving when compared to a 5W-30, 10W-30 or a 0W-30 viscosity motor oil.

For better performance and protection we recommend using Signature Series 0W-30 100% Synthetic Motor Oil (SSO). This is the top performing AMSOIL Motor Oil for gasoline powered light trucks and passenger cars. It uses race-proven technology and provides unsurpassed fuel efficiency and better wear protection than other conventional and synthetic motor oils. It is a 35,000 mile/1-year change interval motor oil. Use it in conjunction with AMSOIL's Super Duty Oil Filter's that specify a change interval of 12,500 miles/6-months, whichever comes first.

Question: Could using a 5W-30, 10W-30, 0W-30 or even a 10W-40 or 20W-50, oil in my vehicle which specifies a 5W-20 oil void my new car warranty?

Answer: Absolutely not. Vehicle manufacturers only recommend using motor oils meeting certain viscosity grades and American Petroleum Institute service requirements. Whether a motor oil is a 5W-20, 5W-30, 10W-30, 0W-30, 10W-40 or 20W-50 (for racing and high performance applications in, for example, a Cobra R Mustang) or even a synthetic vs. a petroleum based oil will not affect warranty coverage. The manufacturer is required by Federal Law 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 failure. In addition, the Federally mandated Magnuson - Moss Act states that a manufacturer may not require a specific brand or type of aftermarket product unless it is provided free of charge. If your dealership continues to tell you that you must use 5W-20 motor oil and or/ a specific brand of 5W-20 motor oil, then ask them to put it in writing. Their position is inaccurate, and, in fact violates existing law.*

Additionally, if there is ever a question of whether or not a particular motor oil was the cause of an engine failure make sure to get a sample of the used oil in a clean bottle, typically 6 oz. minimum. The oil can then be sent to two independent testing labs for analysis. This is standard procedure for most commercial vehicles, trucking, construction/excavation and fleet companies and there are numerous certified test labs all over the country. Remember, a knowledgeable and informed consumer is your best defense against being taken advantage of by a car dealership service center.

* Note: If a car or truck dealership, service center or other business states that using AMSOIL motor oil in your vehicle will void your new car warranty, ask for that statement in writing and send it to AMSOIL technical Services. If the business won't provide the statement in writing send AMSOIL Technical Services a letter identifying who made the statement, the name and location of the business and what the statement was. AMSOIL will then send a letter to the business informing them that their position is inaccurate, and, in fact, violates existing law. Your name will be held in confidence.

AMSOIL mailing address: AMSOIL Inc., AMSOIL Bldg., Superior, WI 54880

For better performance and protection we recommend using Signature Series 0W-30 100% Synthetic Motor Oil (SSO). This is the top performing AMSOIL Motor Oil for gasoline powered light trucks and passenger cars. It uses race-proven technology and provides unsurpassed fuel efficiency and better wear protection than other conventional and synthetic motor oils. It is a 35,000 mile/1-year change interval motor oil. Use it in conjunction with AMSOIL's Super Duty Oil Filter's that specify a change interval of 12,500 miles/6-months, whichever comes first.

For those consumers that still must use a 5W-20 oil, even after reading this informative article, AMSOIL does manufacture a 5W-20 synthetic motor oil, called XL-5W-20. AMSOIL's 5W-20 synthetic motor oil provides outstanding wear protection and increased power, performance and fuel economy in high and low temperatures and also meets and exceeds the Honda, Ford and Chrysler fluid specifications.

 

Interesting, thank you. I use R.P. in my rig.

S.R.

 

There have been numerous reports from people of dealers using 5W 30 in their JKs, so it isn't a big issue.

There really is a lot of variance with dealers. SOme will actually warranty obvious off-road damage, others will make up excuses not to warranty obvious manufacturing flaws. Find a good dealer and you shouldn't have many issues.

 

You can run straight non detergent HD30 TRACTOR oil in the damn thing and as long as you keep it changed regularly, it'll run just as long as any other oil....cept maybe synthetics. It's all hype either way you look at it. One way to help offset the CAFE standards and the other way to line the pockets of synthetic oil companies. I'm just doing like my owner's manual says. I don't know why the hell that's so hard for some people to do.

 

vans, The link you provided is written by an Amsoil affiliate. Not to say the article is wrong, however it could be misleading.
This federal law regulates warranties for the protection of consumers. The essence of the law concerning aftermarket auto parts is that a vehicle manufacturer may not condition a written or implied warranty on the consumers using parts or services which are identified by brand, trade, or corporate name (such as the vehicle maker's brand) unless the parts or service are provided free of charge.
As far as oils lubricants and fluids, it would be correct to say that the manufacturer could not, under this act, dictate that you must use Mopar brand oil in yor engine, as that would constitute a breach in what the Act was written to prevent. The manufacture can however state that to maintain the engine waranty you must maintain the engine, using oils that meet or exceed the API rating that is listeded in the Owners Manual, to ensure that the OEM standards for quality and performance have been met.
For example if the requirement to maintain the engine in your geographical location requires a certin SAE due to the temperature, and instead you use a straight 90W oil while driving the vehicle in a -20* environment, then the manufacturer would have a valid case for not honoring the waranty on the engine. And say for example the requirement for the auto transmission is a certin API, however you choose to use heavyduty compressor oil, which falls outside the rating for the transmission, then the manufacturer could void the waranty on the transmission based on that finding. These are both extreme examples, but you can see the point.
This Act was written to protect the consumer, however it does not grant the consumer "carte blanche".
If the Amsoil oil you choose to use, meets or exceeds the manufacturer's requirement for the engine in your vehicle, then the waranty could not be voided, for the use of that oil.

"For those consumers that still must use a 5W-20 oil, even after reading this informative article, AMSOIL does manufacture a 5W-20 synthetic motor oil, called XL-5W-20. AMSOIL's 5W-20 synthetic motor oil provides outstanding wear protection and increased power, performance and fuel economy in high and low temperatures and also meets and exceeds the Honda, Ford and Chrysler fluid specifications."
Let it be known that the XL brand of Amsoil is a Group III / hydrocracked base oil, that is not a true synthetic such as Amsoil ASL,Group IV / PAO, but yet the cost is about $5.20 per quart.
Just thought I'd throw that out there.

 

Thanks Lorrel, yes i was aware that is is an Amsoil marketing page and that ANY Amsoil products that does not specifically state "100% Synthetic" will be a blend.

I was making point of the fact that we need to adhere to the API rating rather than the viscosity of the oil (within reason of course).