Effects 10W30 oil can have on 5W30 engine?

[THafeez]

Hey everyone,
Last time I changed my oil, the mechanic recommended using 10W30 rather than 5W30. 5W30 is what the owners manual says to use. He said that because its an older car, the engines seals can wear out and a thicker oil can help to minimize leaks, burning etc...
So what benefits can using a 10W30 have for example in the summer for a car that calls for 5W30?
Can a higher weight oil help an older engine during start up since both oils reach the same viscosity at 212C?
Does 10W30 shear slower than 5W30?
Just asking generally, wanted to know what opinions are out there.
The 2AZFE engine in my car has a timing chain as far as I know.

 

[Rand]

No real difference except in the middle of winter.

10w30 isnt thicker than 5w30 so sounds like they just wanted to get rid
of some surplus 10w30 they got a deal on.

 

[Doog]

I would try a high mileage 5w30 in that engine. My 2008 2AZ-FE runs on 5w20 HM just fine.

 

[Branson304]

What effects does 10W-30 have on a 5W-30 car?

None unless it's really cold.
Really cold.

It's nearly the same viscosity at operating temperature, they are both 30 weight oils. But 10W-30 is THICKER at start up, causing oil to flow much slower to all the internals of the engine. It doesn't really matter until it's cold. If you have leaks & consumption then using a high mileage 5W-30 oil would be a good idea. And if you really want the thicker route, go to 10W-40 which would actually be thicker at operating temperature.

 

[Astro14]

Your mechanic might be great at fixing cars, but his oil advice is way off...the 10W30 won't be any "thicker" at operating temperature and will make zero difference in slowing leaks. In fact, many 10W30 are THINNER at operating temperatures than a 0W30...completely different than your mechanic's supposition...and by the way, your car doesn't really seem "older" to me...but that's a matter of perspective, I suppose...

The suggestion that you try a high mileage oil is a good one - they have seal conditioners (softeners) that can make a big difference in seal leaks...they don't do much for gaskets...but they may help in your case.

 

[barkingspider]

Your Toyota cannot tell the difference. 10w30 is fine. Unless the weather is well below freezing

 

[ARCOgraphite]

10w30 is not a "thicker" oil per se. It May have a tad bit better HTHS and more oil and less VM polymers but not like the days when 5w30 was pushing the multigrade envelope and poor quality VM were used.

the 5w vs 10w is more about the cold temp when the oil clouds then gells into a thick honey. This is at -25 or -30 C.


If you want "thicker" run rotella T triple-protect 10w30 SM Dino - though I don't think they make it anymore (?)
I don't know what a good substitute is - though I run Valvoline racing 10w30 in the generator for a great pseudo HD ODPE oil.

Most mechanics don't know much of anything about oil.

 

[supton]

I noticed slower cranking at like 11F on 10W30 as opposed to 0W20. Above that I don't think I noticed a difference. How much of that was the 10W vs the 0W, and 20 vs 30, I dunno. But I plan to go back to 0W before December.

I'm kinda thinking that 10W is fine from April-ish to October-ish. I wouldn't buy it unless if it was on sale (and in my case, it was), but if it's a good deal, and you will "use it up" before winter, run it. Starting to get kinda late though to run 10W, though, and 10W will reveal a weak battery faster than 0W or 5W will.

Personally I think your mech was trying to use up some cheaper oil, or (perhaps) doesn't understand what the 10W means.

 

[crazyoildude]

+ 1 on the high mileage oil

 

[bigt61]

In the 80s and 90s, the 10W-30 oil was less volatile than the 5W-30 oil (more VIIs) and held up better through the life of an oil change - in other words, less of it burned off. Even then, people did not check their oil and just showed up every 3-5k for a change so 10W-30 was a safer choice for maintaining proper oil level. The 5W-30 oil available now is much more robust and meets API SN. I doubt there would be much volatility difference now and cold start issues running a 10 vs a 5 would be minimal unless you're talking extreme negative number cold. In any old or new car now, in most cases, 10W-30 vs 5W-30 is no big deal. AFAIK - 10W-30 is pretty much an obsolete grade, though many old cars specify it - like my 94 Bonneville.

 

[THafeez]

Thats for the feedback guys. I always learn something new here everyday.
I have M1HM 5W30 ready for the next change. I think I'm going to put a quart of MS5K which was leftover from the last change and 3 qts of M1HM. I don't want to introduce too many detergents and seal conditioners to the engine as I don't know what it looks like in there except for varnish under the oil cap. Is that okay?
After that oil change I'll check and see if its burning oil and then either put 1/2 MS5K and 1/2 M1HM or go all the way with M1HM or go back to regular dino.
Is that fine?
I'm not looking to do a fast cleaning. Just using good oil, getting top tier gas and using techron every 2-3k over the next 10k miles will probably do the same job as BG109 or the sort.

 

[demarpaint]

Hello to a fellow Long Islander! As already mentioned, skip the 10W30 and try a 5W30 HM oil.

 

[bigt61]

MaxLife Blend 5W-30 is likely your best bet long term and year round. Since you've already bought the M1 HM, go ahead and use it - with or w/o your blend - it won't make much difference in that old girl. You can always use the MS5K as top off oil if the M1 HM starts a leak.

 

[jongies3]

The 10W and 5W only matter at temperatures below freezing for a cold start, obviously, the 5W will flow faster than the 10W. Operating temperature viscosity for both is a 30wt and stays there.
Since you live in NY, I'd go with the 5W with winter around the corner, myself. I run 5W-30 in my Tacoma year round with no issues and it's at 108k miles currently.

Pretty sure most the 02 and newer Ford Crown Vic cabs in NYC all run on 5W-20 year round and you've likely seen the abuse those cars deal with on the daily and last half a million or more miles.

 

[Bgallagher]

better off running a HM oil if that is the concern. 10w wont make a difference.

 

[Nickdfresh]

Some used to say use a thicker grade in older vehicles to increase compression. I think that is a bit of dated thinking and I'd stick to 5W-30, maybe a high mileage one. That being said, I doubt 10W-30 will do any harm even in winter in eastern NY...

 

[JBinKC]

If you are speaking strictly about conventional oil only I think the advantage to using a 10 W 30 is it is less prone to shear during the summer months thus you likely can slightly extend an OCI. Given the few UOAs on here using conventional oil I have seen a few of them shear to a 20 w oil eq on mileage below manufacturer OCI guidelines.

 

[Evili]

Keep using the 5W30. Change your mechanic instead.

 

[SatinSilver]

On the 05 Matrix that oil cap says 5w30 but I think it was back spec'd to 5w20. I think the TGMO oil application chart says 0w20 is fine for Canada. So I used 0w20 but it is Maxlife full synthetic. So the seals will be softened and conditioned a bit and allow her to leak like a sieve. The previous oci was MC 0w20 syn-blend but who knows they could have used 5w20 syn-blend. It didn't use any measureable amount of oil over 9500 miles.

 

[BigD1]

Have seen 10W-30 conventional oils that have better NOACK volatility numbers than their counterpart 5W-30.