Is 5W30 oil ok?
5/15/07, 10:37 AM
#1
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Is 5W30 oil ok?
I bought some royal purple 5W30 oil to put in today, and it wasn't until after I bought it that I remembered the car takes 5W20. 
Is it ok to put this oil in, or does it absolutely positively have to be 5W20?
thanks
Is it ok to put this oil in, or does it absolutely positively have to be 5W20?
thanks
5/15/07, 10:41 AM
#2
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I would absolutely, positively NOT use 5W30 in my car...
5/15/07, 10:44 AM
#3
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Whereas we are at sea-level here, I would not advise it. That is more for elevation's, or colder times. We are getting warmer now here. Just run it for while then replace with full synthetic. No harm, no foul; You used a good oil anyway.
5/15/07, 10:49 AM
#4
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Thanks for the quick replies!!
I don't think anyone around here carries RP 5w20, guess I'll go with mobil1
5/15/07, 10:49 AM
#5
Team Mustang Source
I'm using 5-30 in mine for an experiment. I used 5-20 Mobil1 last time and had an oil analysis. Showed high iron and copper readings. I'm trying 5-30 to see if the readings come down. Car runs fine, just as good as it did before, gas mileage is only down like 1mpg.
5/15/07, 11:21 AM
#7
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Since I got the car 2 years ago my dealer only put in 5W-30, because 5W-20 does not exist here. I've never had any problems so far (25k miles) and upon checking the oil at every 5k miles it was in perfect condition.
However, if I were in your situation I'd just go back to the store and change it for 5W-20.
However, if I were in your situation I'd just go back to the store and change it for 5W-20.
5/15/07, 12:07 PM
#8
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oh no your car is going to explode and die and fall into a million pieces all over the road. the end is near. 
been running 5W30 since the start, no issues here, check it regularily, no oil analysis yet. would be curious what your results are theedge67.
been running 5W30 since the start, no issues here, check it regularily, no oil analysis yet. would be curious what your results are theedge67.
5/15/07, 12:22 PM
#9
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I just put together a small comparative table for 2 types of 5W-30 oils and one 5W-20. Use it and interpret it any way you want, I'm sticking to my opinion that 5W-30 does NOT harm the GT engine.
5/15/07, 12:25 PM
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5/15/07, 01:47 PM
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The following is from a major US engine oil manufacturer:
Question: My owners manual species 5W-20 oil. Do I really need to use 5W-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 oil?
Answer: You do not need to use a 5W-20 oil. Do not let your dealer scare you by telling you that you have to use it 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 oil you want to use.
The main reason 5W-20 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 Ford and Honda'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.
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.
Here are the facts behind 5W-20
Question: My owners manual species 5W-20 oil. Do I really need to use 5W-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 oil?
Answer: You do not need to use a 5W-20 oil. Do not let your dealer scare you by telling you that you have to use it 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 oil you want to use.
The main reason 5W-20 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 Ford and Honda'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.
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.
5/15/07, 01:49 PM
#12
5/15/07, 01:50 PM
#13
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I returned the 5w30 and got some mobil1 5w20 and put that in today. The oil that I drained was BLACK. I don't know if it is supposed to be that black, but it only had a little under 3000 miles on it. The oil was just liquid black, like tar but still oil. Is that a normal thing? It had me worried, but I worry about every little thing about this car.
5/15/07, 01:55 PM
#14
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Would have saved me a trip to wal-mart 
thanks for the information though!
5/15/07, 01:58 PM
#15
Team Mustang Source
Probably shouldn't be that black...but it depends on how you drive it. Highway miles are easy, city, wot, racing miles are hard on oil. Color does not necessarily indicate dirty either.
5/15/07, 10:49 PM
#18
5/16/07, 04:49 AM
#20
Legacy TMS Member
My only concern are the cam phasers and the elevated oil pressure (compared to non VVT mod motors) used to operate the mechanism. That aside, I'll keep using 5w20, people [censored] about how oil companies are ripping us off anyway and the deplorable rate at which americans consume oil and while I guess a V8 mustang is no different than large SUV or truck, it still helps contribute to the whole. If running 5w20 increases fuel mileage by 1 mpg, multiplied across (in this case Mustangs) thats a coupla hundred thousand mpgs saved. There are many little things that could be done to help increase fuel mileage on the macro level, but since they are essentially invisible on the micro level, people dismiss them as useless. Another useful tactic would be a switch from using air in tires to nitrogen - which should be the factory fill - since it migrates from the tire at a slower rate (my own personal exprience has shown almost a year with no appreciable air pressure loss except due to temp variations) and tires that are properly inflated also help prevent an increase in fuel consumption.