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So I have been using mobil 1 10W-30 for about 50,000 miles now because I used to think it was a better to run a bit thicker oil. But going through school made me realize alot different about oils. Now here is my question, can I go back to using mobil 1 5W-20 without harming or hurting the engine? I know using 10W-30 makes my oil pump work harder and I would rather go back with the 5W-20 like honda recommends, but am just concerned about any negative effects it might have. The weather here usually is around 100 degrees in the summer and gets down to 20 or 30 degrees in the winter. What is everyones input about this? Should I go ahead and switch back or keep using 10W-30?

 
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What i want to know is, Since 5w-20 is so thin, and when it gets hot becomes even thinner, how does it protect the engine well.

 
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Viscosity in motor oil is the index improvers (additives) that modify the oil so fluid flows more consistently over a wide temperature range.

Ideally, oil should be thin enough to flow easily when an engine is cold and remain thick enough to protect an engine when it's hot. Automakers specify grades according to the temperature range expected over the oil-change period. The lower the number, the thinner the oil and the more easily it flows.

In 5W-30 oil, for example, the two numbers mean it is a "multiviscosity" or "multigrade" oil that is effective over a range of temperatures. The first number, 5, is an index that refers to how the oil flows at low temperatures. The second number, 30, refers to how the oil flows at high temperatures. The W designation means the oil can be used in winter.

A popular belief is that 5W-30 oils, despite their designation, are too thin to protect vital engine parts when they get hot. However, laboratory tests measured the viscosity of oils under high-temperature, high-stress conditions and found essentially no difference between 5W-30 oils and their 10W-30 brand mates. But at low temperatures, the 5W-30 oil flowed more easily.

Viscosity grade is important, so be careful. Recommendations vary with the make, engine, and model year of the car, so check your owner's manual. And always look for the starburst symbol on the label, indicating that the oil meets API (American Petroleum Institute) requirements.

Oil does not wear out, it just gets dirty. Be sure to look for re-refined oil with the starburst API symbol in the viscosity you need.

I got this off of another webiste.

I am still curious to know whether I should go back to 5W-20 or stick with 10W-30 since I have used it so long?

 
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im no expert, but since it all does the same thing, i dont think it would harm anything. I would do a flush first though. im thinking of possibly switching to a thicker oil,, What would be my best bet?

 
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In the summer, going with thicker oil is a good thing, in the winter you should use the thin stuff.

 
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Bump

 
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you can go back to 5w20 without any issue.

 
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cool, I was just wondering, but do you think it makes any difference to have the 10W-30 in there compared to the 5W-20? I mean it stays pretty hot here year around, but I want to make sure I get the most out of my engine?

 
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The only reason I am concerned is because I feel that over the past 50k miles, my engine has adapted to 10W-30 and putting 5W-20 back in would probably less lubricate everything.

 
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YES! switch back. there is a reason Honda recommends what they do....

 
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there is a reason why they say 5-20. you get better gas mileage when you run 5-20. quit using 10-30 before your pump breaks. i'm saying it will happen but its happened before, when you go to a thinker oil the parts in the engine get 'stretched' so to say. sorry lack of better wording. but if you go back it might cause leaks in the cylinder bores and other areas. yall dont get pissed about this. its happened in my buick. good luck.

 
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honda recommends switching back to 5w20 immediately if different oil was used during the previoud oil change.

 
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my ride is 63k. i still use 5-20 and will continue until engine dies. i'm sorry but why is this so hard? 5-20 is 5-20 not 5-30. the manual would say 5-30 if it was needed. if your not gonna pay attention to the specifications for the engine just put cooking oil into it and forget about it. its black and white. pick one, screw up your car and pretend you know what your takin about or do what the actual rocket scientists who built the engine tell you to. tough choice.

 
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I use 10w30, and my engines been running very nicely for 100,000 miles. Not a single engine prob. Ive had cluth cylinders fu** up, but thats it. I live in a hot state as well. We have about the same temp's year round tx/az. I was wondering the same thing as you though.

Im turbod, does that make a difference? I figured a thicker oil would be better, it heats up more, correct? with how much faster the parts are moving? The coldest it gets here during the year, is about 40 at night, and 50-60 in the day. Thats the winter, and it doesnt ever reach below that, well very often. its 110 out right now I bet.

 
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The "rocket scientists" who buiilt the engine don't think of the fact that some of us pound the **** out of our cars. Its not black and white. Thick oil stays cooler at higher temps, which is why you'll see people using 30 and 40 weight oil in race cars, regardless of what the hell it says in the manual. Its an economy engine, run it hard for a while and you'll learn it can't stay cool for very long. First line of defense is the oil in the crank case.... overheated oil breaks down, ruins bearings and ultimately kills your motor. Brand A 5W20 isn't the same as Brand B, and synthetic 5W20 isn't the same as conventional. So it isn't so black and white, especially with synthetics, which typically run thinner than their spec and protect to higher temps anyways. I've run 5W30 forever, and the car runs cooler, I've run 10W40 on the racetrack when its real hot because I know its gonna keep the oil from overheating. There's no formula, you can run anything you want as long as you keep changing it. Is it wise to run 20W-50 in the winter? No, its like molasses, but if its 100 degrees out and you're doing 30 minute lapping sessions the thought might cross my mind. 5W30 is a good all around oil, it doesn't damage the engine in anyway, but it does protect to a higher temperature than 5W20. Using 0W30 in the winter is better for cold starts because its better to lower temps... but protects just as well as 5W30 when the car warms up.
Most of us who have played around enough know the manual is mostly bullshit on stuff like that. You can't do the long oil changes like it says, you can't go 110K before changing spark plugs, well I guess you can, if you like oil sludge you can do it every 7500 like it says, and if you want to run your gas milage into the ground you can change your plugs when they say, but the rest of us don't.


....anyways, dump 5W30, 0W30, 5W20, whatever back in. Just make sure its synthetic. You can't go back to dinojuice once you've had synthetic in the car.

 
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i change my oil very 3k. i change my plugs every 60k and the rocket scientists know better. ok some of the manual is crap. would you put any other fluid besides HMT fluid in a manual honda tranny? and BTW you CAN go to synthetic and BACK all you want with NO issues.

 
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i know for a fact the only reason honda switched to 5w20 is because it improves the fuel milage, it is safe to run 5w30 or 10w30 and would run 10w-30 in summer and 5w30 in winter if not 10w30 all year round in warmer climates, im a cert aircraft mechanic but im currently working for Mobile oil company, i have read paper work honda sent us back in 2000, really you could run any 10to20w30 oil in very warm climates

 
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You just bumped a 7 YEAR OLD thread.....

 
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lmao xD