5w30 vs 10w30 Full Synthetic In Small Engines

[jonp]

I've switched to 5w30 Full Syn in all my engines to make things easier including my 2004 F150 5.4 which wants 5w20. Much forum reading recommended the switch

My lawnmower calls for 10w30. Safe to switch?

[reddog81]

I've seen various charts that recommend the appropriate weight oil for various engines when operating conditions in freezing cold or 100 degrees+ temps and it seems to make a difference when operating at these extremes. Often times there is overlap for numerous weights of oils in what would be considered normal conditions of 30 degrees up to 100 degrees.

In my non-professional opinion I wouldn't worry about it. I'm sure others will argue that it'll be imminent catastrophe, but won't have any proof...

[metricmonkeywrench]

Most of my gear is Briggs powered, I just run straight 30w through it all and change it every season. Anything more just seems like overkill.

[jcren]

I strongly recomend using a diesel grade oil (or racing, offroad or mototcycle) such as rotella or mystic for small engines. Modern oils did away with the high pressure additives like lead (not our lead, tetra something or other) and sulphur to reduce emissions and polution in modern roller cam engines. Small engines and diesels still run flat tappet cams.

Oops: zinc. Not sulphur. Shouldn't post when tired.

[jonp]

I have a case of HD 20w50 oil. Think that would work? Lawn mower is run 50F to 90F or so and has a Honda engine. Rider has a 17horse Kohler.

[GregLaROCHE]

One thing to know about thin synthetic oil, is that it will run off parts, if the engine is not run regularly. For example six months. The protection against corrosion and rust inside the engine, is a lot better with normal mineral oils in this situation.

[LUCKYDAWG13]

I've switched to 5w30 Full Syn in all my engines to make things easier including my 2004 F150 5.4 which wants 5w20. Much forum reading recommended the switch

My lawnmower calls for 10w30. Safe to switch?

Why was the switch recommended I have a 08 F150 5,4 just turned 110.000
I use 5w20 full syn mobil 1 change every 3K

[tomme boy]

Zinc is the main thing they took out. You can wipe out a engine at the break in if it is not in the oil.

[john.k]

Flat lifter engines wont survive without zinc,or a suitable replacement additive,excessive cam and lifter wear guaranteed.

[Dieselhorses]

That Triton motor has extremely small oil ports in cam, crank etc.! I think it calls for 5W 20? And synthetic WILL run off parts! My little Corolla can use either 0W-20 or 5W-20. I use the 5 in warm weather.

[woodbutcher]

[smilie=s: How quick can a cam lobe be ruined on a new engine?In less than 20 minutes on the break in run.That`s20 minutes at 2000 to 2500 RPM for the initial break in on a new build.
Good luck.Have fun.Be safe.
Leo

[sigep1764]

We have always used straight 30w Mobil, not synthetic, in the air cooled engines. The Grasshopper went 3000 hours before needing a v twin short block, but it died from overheating due to a clogged fan shroud that hadn't been cleaned ever. It was covered and unseen. These air/oil-cooled motors run at some high temps. In my experience, they benefit from thicker viscosity oils that coat well and keep oil pressure a little higher. Motorcycle gets Mobil 1 4Tec 10w40 and the K5 Jimmy gets 10w30 Mobil 1, the LT1 in it is a roller cam/lifter motor. Different platforms can benefit from oils designed for them. Again, this in my personal experience.

[Elkins45]

Who makes your engine? My Briggs recommends straight 30w under most conditions and says you can use 10w-30 but it will burn more.

My Mazda owners manual says to use 0w-20 in you live in the USA but to use 5w-30 if you live anywhere else. My point is that the recommendations are often made based on EPA mandates rather than on what the engineers say. I wouldn’t ever run an oil with a lower viscosity than than the manual specs.

[dkf]

That Triton motor has extremely small oil ports in cam, crank etc.! I think it calls for 5W 20? And synthetic WILL run off parts! My little Corolla can use either 0W-20 or 5W-20. I use the 5 in warm weather.

The Triton motors originally speced 10w30 when they first came out. Then they switched to 5w30, then to 5w20 and within the last few years back to 5w30 again. The changes to the thin oil was nothing but an attempt to try and get a tenth or two of a mpg gain for better CAFE ratings. There was no changes to oil port or oil passage size. Ford was experiencing failures in the later years 6.8l engines in trucks which is due in part why they switched back to 5w30. The cam phasers in the 3V 5.4l actually work better with 5w30. There is no negative to 5w30 in the modulars (tritons) I switched all of mine over to 5w30 years ago. Ford now runs 5w30 in most of their gas engines including the 6.2l which was replacement for the lighter trucks. I run a synthetic oil. For very cold climates and cold winters 0w30 synthetic works very well.


My grandfather was a mechanic of small engines, mainly lawnmowers for most of his life. He always told me to use a straight 30 or 10w30 and add some STP or Lucas. I did that for years but have been running a 15w40 diesel oil for quite a few years and skip the stp or Lucas. Sometimes a 10w30 diesel oil too. Years ago regular motor oils had more anti wear additives but that amount has been reduced for emission reasons. The diesel oils still have a high level of anti wear additives like zinc and phosphorus. I always use a non synthetic oil in air cooled engines as from some of the testing I have seen the dino oil does a better at pulling heat out of internal components quicker than a synthetic. Aircooled lawnmowers are pretty hard on oil so It is a good idea to change it regularly and not do long OCIs anyway.

[Elkins45]

Aircooled lawnmowers are pretty hard on oil so It is a good idea to change it regularly and not do long OCIs anyway.

It’s actually sort of amazing most mower engines last as long as they do. If my brother has ever changed or even checked the oil on a mower it would be news to me.

My old boss asked me to look at her mower because it wouldn’t start. The air filter was so clogged that it was completely black. The oil looked like chocolate syrup. How it ever started again was a mystery. As harsh as the conditions are in that crankcase the oil really has to do a good job.

[Brassduck]

the smart person would adhere to the eng builders specs and run what the the specs call for, that is the safe way to go. or just run what ya got, at the worst it'll only cost money.

[dkf]

It’s actually sort of amazing most mower engines last as long as they do. If my brother has ever changed or even checked the oil on a mower it would be news to me.

My old boss asked me to look at her mower because it wouldn’t start. The air filter was so clogged that it was completely black. The oil looked like chocolate syrup. How it ever started again was a mystery. As harsh as the conditions are in that crankcase the oil really has to do a good job.

Yeah, the lawnmower is usually the last thing people think of or want to maintain. When the season is over put it in the shed and don't worry about it till next year. Aircooled lawnmowers by nature run hot which is hard on the oil. Then many of them do not have oil filters and rely on a "slinger" to do the lubrication. Any mower with a slinger I make sure to keep the level up at the top level all the time.

I got a self propelled Hahn (late 70's or early 80's with an aluminum deck) from my neighbor for free. Already had a non self propelled Hahn but the price on this one was right. He was going to throw it away. Straightened the crank shaft, new crankshaft seal, put a set of chrome rings in, carb cleaning, points & condenser, new hub & blade and a little cleaning. Have been running it for over 15 years. The older mowers were built well and if you can do a little work on them they last practically forever. Not so much with the newer stuff.

[GregLaROCHE]

The best oil is freshly changed oil. No matter what you use, don’t forget to change it when the manufacturers say to, or earlier if you want to be on the safe side.

[Bookworm]

My Briggs push mower get straight 30w detergent, changed once a year - if it needs it or not.

My zero turn gets straight 30w, every 100 hours, with a filter change.

[Messy bear]

I wouldn't run diesel oils. they have way more additives that just end up in combustion chamber and on plug. years ago, you could get low ash oils, I ran those in hopped up air cooled engines. now all gas engine oils are low ash. in a high compression engine, the diesel oils lead to pinging and preignition. just stick with whats recommended and you will be fine but like others have said don't drop below viscosity rating.

[RogerDat]

I was straight 30 weight detergent for most of my life. It is what the Briggs manual called for. However as I did less maintenance on my own I found a very experienced small engine mechanic and his wife both well certified by manufacturers. They recommend 10w-30 or even 10w-40 for summer hard usage.

I will say that "10" at the front does make a big difference in starting the generator and large snow blower in the winter. Pull starting an 8.5 or 10 HP motor cold with straight 30 weight I would generally want to put a 300 watt shop light on it to pre-warm. Of course if the power was out and I was starting the generator.... yeah 10W-30 is a much better choice there. I'm not paying for synthetic. I change the oil seasonally so high end is probably a waste. One more good use for a piece of sheet lead. Flexible trough or funnel for draining oil.

[jonp]

Im thinking of synthetic because I always seem to have some left over after doing the vehicles and id like to just use it up

[Elkins45]

I still wouldn’t want to use a 5 weight oil unless the maker says it’s OK. Maybe if I mixed it with some straight 30.

[dkf]

I still wouldn’t want to use a 5 weight oil unless the maker says it’s OK. Maybe if I mixed it with some straight 30.

When the engine is at operating temperature both oils will be 30 viscosity oils. Amsoil synthetic SAE30 oil with no viscosity modifiers actually has the same numbers as a 10w30 in both cold and warm temperatures due to the basestock used.

[15meter]

Worked with an oil additive research lab a number of years ago. They formulate and market the additives that get sold to the engine/hydraulic oil mfg. I asked the lab manager for recommendations on oils for my own use. His first recommendation was to use the same brand EVERY time, next use the recommended weight and change at the recommended interval. Brand wasn't as important as using the SAME brand every time and make it a recognized name brand, not bubba-world/ flavor of the week in their house labeled jugs.

Never lost an engine, most went way past what was considered "normal" life. Was taught to do most of what was recommended by my dad. Just got confirmation from the boys at the research lab.


Guess what dad learned keeping P-38's and P-39's going was the right way to do it.

[Dieselhorses]

Paying attention to oil specs/requirements is a good thing. All the best oil in a small engine won't do justice if you run gas with ethanol in it. BUT, everybody does anyway.

[samari46]

My little riding mower gets straight detergent 30w oil, the Kubota oil I use is straight from the dealer first diesel engine for me. regular lawn mower gets straight 30w oil and filter change. Gas for my saw,generator, and trimmers all get 30 w oil. Gas gets Stabil and reccomended oil additive. The prize goes to my little homelite chain saw.Check,gas and clean the spark plug, check and clean air filter and it lasted almost 20 years.Had a huge pecan tree fall due one of our hurricanes. Disected that sucked with the homelite except the main trunk. called in a crew who finished what I started and the $150 was worth it. I asked them what do they do with the wood.As some people use the wood in their smokers. Nope they just burned it. Frank

[winelover]

I have a 25 year old commercial Honda self propelled LM that I ran Mobil 1 10W-30 full synthetic since day one. Engine still going strong and starts on the first pull. Just bought a new Honda LM and have the owners manual right in from of me. Recommended oil is still 10W-30. However, the chart also state that 5W-30, as well as straight 30 weight is OK. The operating outside temperature range is the deciding factor.

Straight 30 weight has the narrowest temp range of 50 to just over 100 degrees. Both the 5W-30 and the 10W-30 range is between 25 degrees to just over 100 degrees. Honda recommends API Service category SJ or later oil. Notice Using non detergent oil can shorten the engines service life. This is straight from the horse's mouth.

I keep full synthetic 10W-30 and 5W-30 around for my multiple vehicles. I plan on staying with 10W-30 but would use the 5W-30 in a pinch.

BTW, the new Honda purchase is because the Hydrostatic transmission is going on the older one and the cast aluminum deck is now a side discharge from multiple hits, from rocks, that seem to grow everywhere in Arkansas. Replacement Honda now has a steel deck.

Winelover

[winelover]

When I was researching mowers, quite a few mowers have engines that don't require any oil changes, ever. Just keep topping it off. Kohler for one, IIRC............no thanks.

Winelover

[Tripplebeards]

Your 2004’ 5.4l is going to tick no matter what oil you put in it.lol I have one that a crew cab. I’ve managed service departments for 25 years. Also worked for ford for short period of time. That was a horrible motor. Don’t buy 04’ through 08’ as they all sound diesels after 45,000 miles from the cam phaser issue. When taken into the dealer to do the “repair” they ALL tick again in 20K. Can’t beleive for never recalled them. Mine has ticked since 45k and goes through 2 quarts of oil every 2K.lol it now has a 145 k on it and is still running strong...besides rusting quite a bit.

As far as oil goes. The numbers between the “W” are the high and low temp ratings. Oil is oil, you literally can use what ever oil you want within common sense and reason as long as you check the level and change it often. There is no big mystery or science about it. I can still remember years ago...And make sure you never buy a turned in Hertz and Avis rental cars, AKA program car. I refused to change there oil when I managed one of the local centers being they wanted us to put standard oil in their synthetic only vehicles. Apparently they were trying to save money and didn’t care and told me that’s the way they have always done it! Instead of them paying an additional $12 for the correct oil Avis went somewhere else that would put stand oil in their cars. Hertz paid for the upgrade. It’s set that way all over the country at most of the quick lives with rental cars. Imo if I were you I wouldn’t worry about being heavy or or light up or down one weight rating on your oil. All that’s for is for hotter or colder weather conditions so it doesn't turn into tar in extremely cold temps that we get in WI.


When I was a kid I use to pour in some 15w40 instead of motor honey to take care of ticking motors in a few $200 clunkers I bought. Takes care of the tick and doesn’t hurt a thing, till it get to be single digits outside. Then your motor turns over slow as molasses being the thicker weight oil hardens with cold temps, that is till it warms back up.

[Elkins45]

I would think if anything could benefit from a synthetic oil it would be an air cooled small engine.

Somewhat off topic, but my Mazda is the first engine I’ve owned that burns any oil between changes. I think the 0w-20 combined with higher compression causes some of it to slip past the rings. I’m continuing to use it and changing at 5K, but as soon as the powertrain warranty expires I’m going to start using up the stock of 5w-30 I have left over. If it’s good enough for every country except the USA then it’s probably good enough for me.

[Tripplebeards]

I can remember when they introduced full synthetic Harley Davidson oil. I was the service manager at the local Harley Davidson shop back in the early 2000‘s when they first introduced full synthetic oil I had so many people yelling and screaming at our shop because their motor sounded like loose boxes of change rattling in their pocket.lol The motor sounded like they literally were going to grenade and come apart. The quickfix was we always just dumped the synthetic oil right back out of it and put regular oil back in it. Needless to say the motors quieted right back down immediately. Full synthetic is just too thin and burns and seeps/slips past the rings in most vehicles. IMO you gotta have a vehicle with a very tight tolerances for full synthetic oils to keep it from burning and eventually making your engine knock. Full syn vs reg oil is like comparing crisco oil to cold maple syrup. I get a kick out of it when it first came out manufactures said you could run it 5000 miles instead of 2 to 3 with regular oil now it’s 10 to 15,000 miles plus and nothing has changed In the manufacturing of Synthetic oil’s it’s basically the same as it was when it first came out. Synthetic oil is the same as it was when it first came out other than they have added new Detergents in it to clean the inside of your motor while it lubricates. The big problem is that the average consumer is lazy and inconvenienced not wanting to want to come in to get their oil changed so the manufacturers just back off the Oil change recommendations a few more miles.

[jmort]

There are full synthetics, synthetics, and semi-synthetic blends
Full synthetics like Red Line etc really reduce friction
Stick it on a dyno and you get 10 plus HP/torque
As someone mentioned above, if you have the oil tested, you can run it as long as it passes. With the right filtration, that can be indefinately. It only needs to be replaced when it get dirty or the filter is clogged. In ships they just swap out the filter and test the oil. The oil lasts a long, long time.
The 10 to 15k oil changes are only possible with a really good synthetic oil filter.
You save a lot of time and money if you do it right, even with the hefty upfront charge.
I oil change in place of 3 to 5, less engine wear, and better milage.
Lately, I have switched from Mobil 1 to Motorcraft Synthetic Blend with Lucas Oil Stabilizer as that is what the local shop carries. Used to use Wix oil filters. Now, Motorcraft, as that is what the local shop has. So I could go 5k. Actually, much less, as I only drive up to 3k a year.
As to the O/P, I use some type of synthetic in everything.
Less friction/wear makes sense. More power is a bonus.

[Handloader109]

Your 2004’ 5.4l is going to tick no matter what oil you put in it.lol I have one that a crew cab. I’ve managed service departments for 25 years. Also worked for ford for short period of time. That was a horrible motor. Don’t buy 04’ through 08’ as they all sound diesels after 45,000 miles from the cam phaser issue. When taken into the dealer to do the “repair” they ALL tick again in 20K. Can’t beleive for never recalled them. Mine has ticked since 45k and goes through 2 quarts of oil every 2K.lol it now has a 145 k on it and is still running strong...besides rusting quite a bit.

As far as oil goes. The numbers between the “W” are the high and low temp ratings. Oil is oil, you literally can use what ever oil you want within common sense and reason as long as you check the level and change it often. There is no big mystery or science about it. I can still remember years ago...And make sure you never buy a turned in Hertz and Avis rental cars, AKA program car. I refused to change there oil when I managed one of the local centers being they wanted us to put standard oil in their synthetic only vehicles. Apparently they were trying to save money and didn’t care and told me that’s the way they have always done it! Instead of them paying an additional $12 for the correct oil Avis went somewhere else that would put stand oil in their cars. Hertz paid for the upgrade. It’s set that way all over the country at most of the quick lives with rental cars. Imo if I were you I wouldn’t worry about being heavy or or light up or down one weight rating on your oil. All that’s for is for hotter or colder weather conditions so it doesn't turn into tar in extremely cold temps that we get in WI.


When I was a kid I use to pour in some 15w40 instead of motor honey to take care of ticking motors in a few $200 clunkers I bought. Takes care of the tick and doesn’t hurt a thing, till it get to be single digits outside. Then your motor turns over slow as molasses being the thicker weight oil hardens with cold temps, that is till it warms back up.

Not that bad of an engine. I've got an '05 that I bought with 98k on it and it is now just under 500 miles short of 200,000. Doesn't tick. I run 5w-30 or 5w-20 (sticker on truck says use 5w-20) usually a Valvoline synthetic blend. Changed every 10k-15k miles since I've had it. You guys that are stuck on 3000 mile oil changes are wasting money, time and oil. I've run every car and truck I've owned way over 100k miles before getting rid of them and never have had engine fail due to oil or lack of oil. Truck uses about a quart every 6-8K miles.

[15meter]

When I was researching mowers, quite a few mowers have engines that don't require any oil changes, ever. Just keep topping it off. Kohler for one, IIRC............no thanks.

Winelover

Guy at the gun club was bragging the other day that he hasn't changed oil since his mower was new over 20 years ago.

But the standing joke about him at the club for why he parks at the back of the parking lot at the club, close to the road is so he wouldn't waste all that gas driving the extra 65 feet BOTH ways coming and going from the gun club.

[Elkins45]

There are full synthetics, synthetics, and semi-synthetic blends
Full synthetics like Red Line etc really reduce friction
Stick it on a dyno and you get 10 plus HP/torque
As someone mentioned above, if you have the oil tested, you can run it as long as it passes. With the right filtration, that can be indefinately. It only needs to be replaced when it get dirty or the filter is clogged. In ships they just swap out the filter and test the oil. The oil lasts a long, long time.
The 10 to 15k oil changes are only possible with a really good synthetic oil filter.
You save a lot of time and money if you do it right, even with the hefty upfront charge.
I oil change in place of 3 to 5, less engine wear, and better milage.
Lately, I have switched from Mobil 1 to Motorcraft Synthetic Blend with Lucas Oil Stabilizer as that is what the local shop carries. Used to use Wix oil filters. Now, Motorcraft, as that is what the local shop has. So I could go 5k. Actually, much less, as I only drive up to 3k a year.
As to the O/P, I use some type of synthetic in everything.
Less friction/wear makes sense. More power is a bonus.

I don’t put a lot of hours on my diesel tractor so I had gone at least three years (maybe 100 hours) between oil changes. When I dumped it this spring I took a sample and had it tested. According to the Wix lab it still had plenty of life left in it, so age didn’t seem to hurt it.

I bought two Wix oil test kits from Rock Auto. I’m going to use the second one to check the 0w-20 in my car when I change it at 5K. I don’t think I ever want to go beyond 5K, but I may want to shorten it if the TBN is low at 5K.

[jmort]

If you have the right oil filter, why not go 10 to 15 k ???
That is best play in my opinion at least financially
But, obviously changing it at 5k would not hurt, and might help
The question, is what qualitative difference is there between 5k and 10k ???
If none, then 10k in a no brainer.

[jonp]

I change my oil at 5,000 mile intervals as its easy to remember. The 5.4 isn't a bad engine as long as you do the maintenance and change the cam phasors every 100k.

The "3 months or 3,000 miles" thing never made any sense to me as I have never run across a manual that said that.

As an aside, our company is on a 50,000 mile interval with our new International A26 units. Manual specifies up to 70k depending on use and avg load weights. This using standard Rotella 15w40

[Geezer in NH]

I have used Mobil 1 in my small engines since the 1970's 5/30. No problems and I Still change on time. 5/30 works for me. Both ofmy lawm tractors ues it and change oil on time with filters.

They are working great.
But why be cheap on oil changes no matter the kind? Penny foolish it seems.
Gheesh keep up the tools eh?

For a 10 buck profit?

[Elkins45]

If you have the right oil filter, why not go 10 to 15 k ???
That is best play in my opinion at least financially
But, obviously changing it at 5k would not hurt, and might help
The question, is what qualitative difference is there between 5k and 10k ???
If none, then 10k in a no brainer.

I read something recently that said the best oil filter is a good air filter—the point being that most of the bad stuff that really damages engines comes in through the air intake.

[john.k]

You have got to be mindful that you dont use oil meant for roller lifter engines in older engines.....this is most modern thin fancy synthetics........I know in some older engines,changing from the thin recommended oil to 15/40 cut oil consumption 90%.A lot of the super thin oils are used to get maker fuel consumption figures down to spec,and the new oils have to be compatible with anti pollution exhaust devices........car makers dont care if your engine is worn out in 6 years.,in fact they prefer it.

[fecmech]

All you ever wanted to know about engine oil and it's ability to prevent wear: https://540ratblog.wordpress.com/
If you scroll down through the intro he lists about 200 different oils he has tested and rates according to their ability to prevent wear. There is a ton of ** involving motor oil, even more than cast bullets and reloading. I personally run 5w-30 Valvoline in all my air cooled engines. It doesn't matter if you run 10-30 or 5-30, both have a 30 wt. viscosity at operating temperature just the same as straight 30 wt oil. If you go to the manufacturers web sites and look under the specs at the various oils both multi viscosity and straight weight oils you can see for your self.

[BD]

Just a bit of anecdotal evidence in favor of synthetics in small engines. We use the little honda eu 2000 generators, (EUI2200 these days I think), hooked up to extra capacity fuel tanks to run job site offices, dewatering pumps, stuff like that where they run 24/7 prior to permanent power lines being run in to the site. Mobil 1 5W-30 in all of them. I ran one pair of those little hondas in tandem for two years around the clock, changing the oil once a week and the plugs every two weeks. Both generators stayed in service on odd jobs for a couple of years after that. If you maintain them, little air cooled motors will go a very long time. It's lack of maintenance, and sitting around for long periods, that causes the issues. Another bit of advice: if your's going to run these little motors only occasionally, run AV100 fuel, or at the minimum non-ethynol gas if at all possible. It's well worth the extra cost to have something that will start right up even after sitting for 9 or 10 years.

[jonp]

All you ever wanted to know about engine oil and it's ability to prevent wear: https://540ratblog.wordpress.com/
If you scroll down through the intro he lists about 200 different oils he has tested and rates according to their ability to prevent wear. There is a ton of ** involving motor oil, even more than cast bullets and reloading. I personally run 5w-30 Valvoline in all my air cooled engines. It doesn't matter if you run 10-30 or 5-30, both have a 30 wt. viscosity at operating temperature just the same as straight 30 wt oil. If you go to the manufacturers web sites and look under the specs at the various oils both multi viscosity and straight weight oils you can see for your self.

That was the blog that got me to run Valvolene Syn Blend as the best dollars to use oil in my cars. Walmart full Syn is cheaper which is why I posted this thread

[DocSavage]

I use Mobil 1 0w20 in my Subaru,5w20 in my minivan and 5w30 in my lawn mower and snow blower. Next change on the Subaru I'm going with 5w20 that way I only need 1 weight for both vehicles