Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
I've been alternating between 10W30 and 0W20 in my two vehicles that are spec'd for 0W20. Zero issues. Heck if you look in other countries the same motor may well be rated for xW30 already (we're special in this country sometimes). And at least one manual has a disclaimer that says thicker oil may be used if towing.
Engines have to work properly when cold, so if you're not using an oil below its rated cold temp it shouldn't matter (might matter to the battery, if it's getting weak). xW30 is thicker than 0W20 at operating temp; but cold 0W20 is thicker than hot xW30--and an engine with 0W20 has to work down to some very cold temperatures.
Engines today are being made with tighter tolerances so therefore you have to use the proper oil that the engine is designed for, thicker oil can't get in between moving parts and journals properly due to it being to thick. I have a 2005 Dodge Neon SXT with the 2.0L engine and the previous owner put 10W-30 in and the engine starts very slowly and the oil light is on when it's running, will be draining the oil and putting the proper oil in which will solve the issue. A real Mechanic will know this.
Engines today are being made with tighter tolerances so therefore you have to use the proper oil that the engine is designed for, thicker oil can't get in between moving parts and journals properly due to it being to thick. I have a 2005 Dodge Neon SXT with the 2.0L engine and the previous owner put 10W-30 in and the engine starts very slowly and the oil light is on when it's running, will be draining the oil and putting the proper oil in which will solve the issue. A real Mechanic will know this.
This is correct. A lot of people have outdated and old-fashioned ideas about motor oil.
I think you will be fine. What i've noticed where it does matter are engines that have some kind of Variable Valve Timing and can throw off the system when using a thicker oil than recommended.
That's because you're getting information from someone that is clueless about motor oils. No basestock with the exception of the esters, will add one mile to the life of your engine. The basestock is just that, the base of the oil or you could call it the carrier package for the additives. A solvent refined Gp I will not wear any differently than a Gp IV synthetic. Here's the deal PL, for the oil companies to make the dough, they have to put on the show. When you buy any of the so called synthetics these days, what you are actually buying is a larger additive package. That additive package is what keeps the engine cleaner because it has more detergents in it. Any additive package that give a synthetic oil an advantage over a conventional or blend can be formulated in a conventional or blend with identical results. Synthetic oils are a premium priced item, shouldn't you get premium results? Synthetic oils have never produced premium results and won't. It's not in their design or its intent. What synthetic oils brings to the game is stability for longer oil changes- that's all folks. There's no more lubricity, no magic in the bottle. So the best for your engine is the correct SAE viscosity, the correct API classification, don't pay a lot for it, change oil per owners manual, sit back and enjoy the ride. Yeah, it's really that simple. There are thousands of cars on the road that uses Walmarts El Cheapo oil that have over 300,000 miles on the clock and running just fine. The million mile Ford van never saw synthetic motor oil, only the cheapest the guy could find. That should tell you something.
So nobody including our brit bud has a clue what synthetic oil bring to the game. Here's some food for thought. There is a test known as NOACK. Noack provides YOU with information about the high heat capabilities of the oil you are using. The test is 1 hour long and the oil is heated to 482F/ 250C. The test is listed as ASTM 5800 if you care to research it. The results are measured in percentage in how much of the oil has evaporated due to the high heat. Your engine will not survive at this temperature, FWIW. A lower number is better. Here's how 5w-30 motor oils stack up.
Mobil One -10.1%
Castrol Edge-11.1
Royal Purple-10.9
Lucas-13.8
The above are all advertised as synthetic based. Here's some of the blends:
Max Life-10.5
A C Delco Blend Dexos-7.9 (that's not a typo)
Walmart Super Tech Dexos-10.5
You can even be an idiot and see that the so called synthetics these days do not offer any high heat protection, a common myth about synthetic motor oils.
In my experience you are dead wrong about there being no difference between synthetic and conventional oils. Living in a climate that sees temperatures dip below zero at times I can tell you that conventional oil does not flow no where near as well as synthetic during a cold start up at very cold temps. I know I run synthetic in my vehicles for this very reason. Studies have shown time and again most engine wear occurs in the first couple of minutes after a cold start up. I'll spend a few bucks more to protect my engine better with synthetic, you can run the cheap stuff.
As far as running the wrong viscosity, be my guest. As at least one other poster commented, manufacturers spec viscosity for a reason, most engines today run way tighter tolerances than they did back when good ole 10w-30 conventional stuff was king. Sure you may not notice any problems right away, but over the long haul repeated use of the wrong stuff can damage your engine.
First and foremost, I think you have to understand what those numbers mean. According to SAE, the "X"w-"X" refers to the flowability at 32 degrees F for "X"w number and the protection provided at 212 degrees for "X" number. That being said there are other things to consider than just numbers; bearing clearances, age and miles on the engine, oil consumption, design of the oil control rings and fuel mileage. If, at brand new, you need 0w-20 or 5w-20 use only that oil by all means to maintain your warranty. However, as the engine gets over 75,000 miles, there may be a need to start thinking about using the next weight/grade up the chain or a viscosity index improver or VII(STP Oil Treatment). Give it some thought... the lower number provides flowability at start up (cold) and the higher number provides protection for all rotating surfaces REGARDLESS of temperature up to 100 degrees Celsius (212F), this includes film formation that remains on the metal to metal surfaces when the engine is not running (very good at start up). These are arbitrary temperatures but provide a baseline for classification and comparison. If at startup your ring clearances have increased due to the age and miles on the engine, you'll burn more oil with a 0w vs a 5w. The higher number again only refers to flowability and protection at operating temps, so if you are finding that you are burning through oil between changes in your high mileage motor, give the next higher weight a try or try some VII. I doubt you'll notice a gas mileage change per tank full or even over the course of a year. I have personally logged over 2+ million miles on personally owned cars and diesel pickups and have never had any problems with going up in SAE weight ratings. Regular oil changes and simple maintenance have helped most of my POV's last well over 300k+ miles. My current whip is a 2001 Ford F250 SD with the 7.3 (325kmiles) and in the winter I run 5W-40 and Summer I run 15w-50 with no change in mileage.
In my experience you are dead wrong about there being no difference between synthetic and conventional oils. Living in a climate that sees temperatures dip below zero at times I can tell you that conventional oil does not flow no where near as well as synthetic during a cold start up at very cold temps. I know I run synthetic in my vehicles for this very reason. Studies have shown time and again most engine wear occurs in the first couple of minutes after a cold start up. I'll spend a few bucks more to protect my engine better with synthetic, you can run the cheap stuff.
As far as running the wrong viscosity, be my guest. As at least one other poster commented, manufacturers spec viscosity for a reason, most engines today run way tighter tolerances than they did back when good ole 10w-30 conventional stuff was king. Sure you may not notice any problems right away, but over the long haul repeated use of the wrong stuff can damage your engine.
LOL @ "when 10w-30 was King". When I first started driving, SAE 30 or 10w-40 was king. Those 428 CJ's and 396 mark IV motors only wanted to run on the SAE 30 detergent based oils. Let me also say, mixing conventional and synthetics makes no difference but DO NOT mix SAE weights you'll lose more than you gain. My personal preference after about 20K miles is to switch to synthetics if they are not already specified and again most all of my vehicles have had over 300K miles on them.
Last edited by Coffeetech10; 07-09-2020 at 03:48 PM..
Reason: add clarity
Unless it decides to get real cold in Phoenix it will do no damage. You will not notice any change in fuel mileage due to the slightly thicker oil, although their might be a miniscule change. You have gone from a 5W oil to a 10W oil.
Honestly, I prefer running slightly thicker weight oils in Phoenix. It's so hot here in the summer, thin oils practically turn to water...
...driving up to Flagstaff would be another story though. Lately I've been doing a lot of driving between the two, so I just stick with recommended. If I were staying in the Valley, 10W30 is no problem.
I totally get that, but there is something to be said for when the manufacturer lists that 5W-20 can be used ANYWHERE (any temperature.)
I truly think the OP is fine, not a thing to worry about, not even a little bit.. Might notice a little different throttle response and ever so slight mileage reduction MAYBE, but, there was a time 5W-20 was laughable, that anything thinner than 5W-30 was like "What?"
I think OP is fine, the part about Phoenix heat just seals the deal. I really think he or she can leave it in there.
Please register to post and access all features of our very popular forum. It is free and quick. Over $68,000 in prizes has already been given out to active posters on our forum. Additional giveaways are planned.
Detailed information about all U.S. cities, counties, and zip codes on our site: City-data.com.
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
