Ok to switch oil?
Thread Starter
JK Freak
Joined: Nov 2010
Posts: 673
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From: Cincinnati, OH
Ok to switch oil?
Anyone running 10w30 oil weight? I'm using 5w30 full synthetic and jeep burns the oil. Thinking about switching to conventional oil at 10w30 weight. Anyone see a problem with this?
JK Enthusiast
Joined: May 2011
Posts: 279
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From: Delaware
Found this. Kind of long, take what you want from it. Question was about synthetic oil in JK.
Yes you can. Synthetic and conventional oil's each have their own benifits. I use a syn blend to get the best of both worlds. Here's what I found on 4wd.com Jeep's forum (i'm a member. lots of good info) long but worth the read.
It feels like there's been quite a few questions on oil lately, might have to do with the changing temps, might just be a coincedence, but here's a quick review on oil.
I'm no engineer, but I am an avid car enthusiast, and take great pride in the things I own, and was taught to take great care of them. With that in mind, here's some info on oil, may be review for some, may be valuable info for others. Please feel free to add and correct as you see fit!
A Used Oil Analysis, or UOA for short, is a great way to start, and can give you a lot of helpful info. Blackstone Labs is one that many use with good results.
For our Jeeps that can range in use from trail only to daily driver to everything in between, they are a great way to help determine your custom oil change interval, or oci for short. Especially if you are dropping big bucks on synthetic or pricey filters. bitog is a great forum for info, but please keep in mind when you're on there that a LOT of people sound like they know what they are talking about, but it is all opinion unless they back it up w/fact.
Different engines also like different oils, in terms of type, viscosity, etc. toss in different types of use, changing weather, etc, and a uoa starts to look really really good in helping to determine your specific oil and oci needs.
By the way, I don't work for any uoa companies, so I benefit in no way from any of you getting a uoa.
I was a mobile 1 10w30 guy, and swore up and down by it. Turns out, Havoline 10w30 seems like it was made for the 4.0 liter in our Jeeps. So that's what I use, and at $12/jug compared to the $25/jug for M1 10w30, I win by saving money as well.
To be honest, I haven't and probably never will do a uoa on my Saab, I'll just change it every 3750 miles and do the oil filter (factory oem) every 7500 miles and call it done. I'm running Chevron 5w30 in it right now, but at the next change, it'll get havoline 10w30 just like the Jeep, just for the sake of keeping it simple and only needing to buy one type of oil.
In all honestly, as long as we change our oils about every 3k miles, little longer if we're on the highway a lot, or a little shorter if we're doing a lot of stop and go (either on or off road), even using the cheapest dino oil out there, we should all pull 100k trouble free miles out of these thumpers. they're the reliable inline motors, and I've heard are pretty darn dependable.
Another big big advantage of uoa's is that they help determine if we're changing oil too early. Imagine if instead of the standard 3k oci, people did oci's and found out that they could actually pull 5k, 7k, 10k, 15k, or even 20k from one oil change. That's a lot less oil being used which saves money and time, and a lot less waste oil being produced!
Good for your wallet, good for the environment, and less time spent on the driveway underneath the car and more time on the porch drinking beer while watching spandex-wrapped hotties bouncing by!
My DD Saab is bone stock, so it probably would be fine on 5w30, but I run 10w30 for two reasons, I run 10w30 in my Jeep, so it's easier just to have 1 type of oil, and secondly, it just helps me feel a little better.
People are arguing and really promoting the newer "thinner" oils. They say it's what we should all run since the newer Vettes run 5w30, I think the Hemi even runs 5w20, I think. However my thinking is that these are newer design motors that were designed for the thinner oil. Our inline motors are a mature design that has had minor revisions, but no major changes. They merely spec'd 5w30 for the fuel economy reasons, sorta like how the 3.0 liter Vulcan V6 built by Ford is essentially unchanged, but over the years, the recommended oil has gone from 10w30 to 5w30, and now, to 5w20. Ford did absolutely no changes to the engine, they merely recommend the thinner oil for the slightly better fuel economy it returns. I remember reading a memo stating that Ford engineers still figured the motor would return approx 80k miles even on 5w20, enough protection to outlast the warranty. Enough protection, but not the most possible protection IMHO.
I could be wrong though, and 5w30 is not the cause for the higher than normal engine failures lately, but I'm certainly not going to use 5w30 in my motor. I'm actually going to bump up to 10w40 soon, after it gets a few more miles on it.
While true that a 0w30, 5w30, and 10w30 are all designed to behave like a 30wt oil at operating temp, these oils are very different. Their operating temp viscosities may be rated the same, but look at the first number. 0w30 is supposed to behave like a 0wt oil when cold, and a 30wt when warmed up. That's a 30-point spread that can only be achieved with polymers that modify the viscosity. The 10w30 has just a 20-point spread, and therefore, there's less viscosity modifiers in the oil, which means there's more oil in the oil, which means more protection for your engine.
Also, those viscosity modifiers don't last as long as I'm comfortable with, they have certainly improved over the years, but still wear out. Extended drains on large spread multi weight oils is a gamble. Once used up, it's just more crud in your oil that's not helping, which means it's hurting.
I prefer oils w/out too big of a spread. 10w30 is ideal. For an older motor, I'd run 10w40, but this also results in a 30-point spread. However, I believe the slightly thicker oil at operating temp is enough of a benefit to use despite this large spread.
Something I would never run is a 5w50, or something w/a similarly large spread. Ideally, I'd love to run a straight 30wt or 40wt, but in real life driving conditions, a multi-weight oil is necessary.
If you're stock and not pushing it hard, you should be able to get 100k out of 5w30, I just wouldn't risk it. Also, fuel economy differences between a motor pumping 5w30 and 10w30 or even 10w40 are negligible. Auto manufacturers do it just because it brings the fleet average down. For those of you considering 5w20, although the viscosity spread is just 15 points, the oil is only as thick as a 20 weight at operating temp. This may be fine for the modern Honda/Ford/Mopar engines, but not for our inline motors. Despite the small spread, 5w20 is simply too thin for our application. Add a load and 100 degree heat, and it's really risking it.
Finally, think of UHaul, I know, they are notorious for the horror stories of their equipment breaking down, which they do, but almost none of it is related to engine oil issues. UHaul does a 5k pm schedule on their vehicles regardless of type. Toyota, GM, Ford, gas or diesel, everything gets 5k oci's. And what does UHaul use? 15w40 fleet dino oil. Doesn't matter if it's a 26 ft diesel w/300k miles or a brand new Ford V8 that's spec'd for 5w20, all UHaul equipment gets 15w40. So much for the myth that modern engines can't use thick oil.
Hence, for now, I will run 10w30, and eventually bump up to 10w40.
BTW, I just returned a Prius that I drove for the past two weeks, and put about 2000 miles on it. I got it right around 3k miles, and returned it w/about 5300 miles on it. Per the owner's manual, it asks for oci's every 5k. Just for fun, I checked the oil to see what type of condition it was in, since the motor shuts off and turns on way more frequently than in a normal car, but the oil looked fine. Didn't even look like it needed to be changed. Showed up dark yellow/light brown on the paper towel.
Oh yeah, the owner's manual stated 5w30 for the Prius no matter what temp range. 10w30 could be used if necessary, but it stated to change back to 5w30 at the next oil change. Surprising, I thought that w/the frequent shutoff/turning on of the engine, it would ask for something lighter in viscosity.
Answer by The Legend
Yes you can. Synthetic and conventional oil's each have their own benifits. I use a syn blend to get the best of both worlds. Here's what I found on 4wd.com Jeep's forum (i'm a member. lots of good info) long but worth the read.
It feels like there's been quite a few questions on oil lately, might have to do with the changing temps, might just be a coincedence, but here's a quick review on oil.
I'm no engineer, but I am an avid car enthusiast, and take great pride in the things I own, and was taught to take great care of them. With that in mind, here's some info on oil, may be review for some, may be valuable info for others. Please feel free to add and correct as you see fit!
A Used Oil Analysis, or UOA for short, is a great way to start, and can give you a lot of helpful info. Blackstone Labs is one that many use with good results.
For our Jeeps that can range in use from trail only to daily driver to everything in between, they are a great way to help determine your custom oil change interval, or oci for short. Especially if you are dropping big bucks on synthetic or pricey filters. bitog is a great forum for info, but please keep in mind when you're on there that a LOT of people sound like they know what they are talking about, but it is all opinion unless they back it up w/fact.
Different engines also like different oils, in terms of type, viscosity, etc. toss in different types of use, changing weather, etc, and a uoa starts to look really really good in helping to determine your specific oil and oci needs.
By the way, I don't work for any uoa companies, so I benefit in no way from any of you getting a uoa.
I was a mobile 1 10w30 guy, and swore up and down by it. Turns out, Havoline 10w30 seems like it was made for the 4.0 liter in our Jeeps. So that's what I use, and at $12/jug compared to the $25/jug for M1 10w30, I win by saving money as well.
To be honest, I haven't and probably never will do a uoa on my Saab, I'll just change it every 3750 miles and do the oil filter (factory oem) every 7500 miles and call it done. I'm running Chevron 5w30 in it right now, but at the next change, it'll get havoline 10w30 just like the Jeep, just for the sake of keeping it simple and only needing to buy one type of oil.
In all honestly, as long as we change our oils about every 3k miles, little longer if we're on the highway a lot, or a little shorter if we're doing a lot of stop and go (either on or off road), even using the cheapest dino oil out there, we should all pull 100k trouble free miles out of these thumpers. they're the reliable inline motors, and I've heard are pretty darn dependable.
Another big big advantage of uoa's is that they help determine if we're changing oil too early. Imagine if instead of the standard 3k oci, people did oci's and found out that they could actually pull 5k, 7k, 10k, 15k, or even 20k from one oil change. That's a lot less oil being used which saves money and time, and a lot less waste oil being produced!
Good for your wallet, good for the environment, and less time spent on the driveway underneath the car and more time on the porch drinking beer while watching spandex-wrapped hotties bouncing by!
My DD Saab is bone stock, so it probably would be fine on 5w30, but I run 10w30 for two reasons, I run 10w30 in my Jeep, so it's easier just to have 1 type of oil, and secondly, it just helps me feel a little better.
People are arguing and really promoting the newer "thinner" oils. They say it's what we should all run since the newer Vettes run 5w30, I think the Hemi even runs 5w20, I think. However my thinking is that these are newer design motors that were designed for the thinner oil. Our inline motors are a mature design that has had minor revisions, but no major changes. They merely spec'd 5w30 for the fuel economy reasons, sorta like how the 3.0 liter Vulcan V6 built by Ford is essentially unchanged, but over the years, the recommended oil has gone from 10w30 to 5w30, and now, to 5w20. Ford did absolutely no changes to the engine, they merely recommend the thinner oil for the slightly better fuel economy it returns. I remember reading a memo stating that Ford engineers still figured the motor would return approx 80k miles even on 5w20, enough protection to outlast the warranty. Enough protection, but not the most possible protection IMHO.
I could be wrong though, and 5w30 is not the cause for the higher than normal engine failures lately, but I'm certainly not going to use 5w30 in my motor. I'm actually going to bump up to 10w40 soon, after it gets a few more miles on it.
While true that a 0w30, 5w30, and 10w30 are all designed to behave like a 30wt oil at operating temp, these oils are very different. Their operating temp viscosities may be rated the same, but look at the first number. 0w30 is supposed to behave like a 0wt oil when cold, and a 30wt when warmed up. That's a 30-point spread that can only be achieved with polymers that modify the viscosity. The 10w30 has just a 20-point spread, and therefore, there's less viscosity modifiers in the oil, which means there's more oil in the oil, which means more protection for your engine.
Also, those viscosity modifiers don't last as long as I'm comfortable with, they have certainly improved over the years, but still wear out. Extended drains on large spread multi weight oils is a gamble. Once used up, it's just more crud in your oil that's not helping, which means it's hurting.
I prefer oils w/out too big of a spread. 10w30 is ideal. For an older motor, I'd run 10w40, but this also results in a 30-point spread. However, I believe the slightly thicker oil at operating temp is enough of a benefit to use despite this large spread.
Something I would never run is a 5w50, or something w/a similarly large spread. Ideally, I'd love to run a straight 30wt or 40wt, but in real life driving conditions, a multi-weight oil is necessary.
If you're stock and not pushing it hard, you should be able to get 100k out of 5w30, I just wouldn't risk it. Also, fuel economy differences between a motor pumping 5w30 and 10w30 or even 10w40 are negligible. Auto manufacturers do it just because it brings the fleet average down. For those of you considering 5w20, although the viscosity spread is just 15 points, the oil is only as thick as a 20 weight at operating temp. This may be fine for the modern Honda/Ford/Mopar engines, but not for our inline motors. Despite the small spread, 5w20 is simply too thin for our application. Add a load and 100 degree heat, and it's really risking it.
Finally, think of UHaul, I know, they are notorious for the horror stories of their equipment breaking down, which they do, but almost none of it is related to engine oil issues. UHaul does a 5k pm schedule on their vehicles regardless of type. Toyota, GM, Ford, gas or diesel, everything gets 5k oci's. And what does UHaul use? 15w40 fleet dino oil. Doesn't matter if it's a 26 ft diesel w/300k miles or a brand new Ford V8 that's spec'd for 5w20, all UHaul equipment gets 15w40. So much for the myth that modern engines can't use thick oil.
Hence, for now, I will run 10w30, and eventually bump up to 10w40.
BTW, I just returned a Prius that I drove for the past two weeks, and put about 2000 miles on it. I got it right around 3k miles, and returned it w/about 5300 miles on it. Per the owner's manual, it asks for oci's every 5k. Just for fun, I checked the oil to see what type of condition it was in, since the motor shuts off and turns on way more frequently than in a normal car, but the oil looked fine. Didn't even look like it needed to be changed. Showed up dark yellow/light brown on the paper towel.
Oh yeah, the owner's manual stated 5w30 for the Prius no matter what temp range. 10w30 could be used if necessary, but it stated to change back to 5w30 at the next oil change. Surprising, I thought that w/the frequent shutoff/turning on of the engine, it would ask for something lighter in viscosity.
Answer by The Legend