10W30 or 10W40 Full Synthetic High Mileage

[Kobe Williams]

2004 Chevrolet Tahoe Has Been Running 10W30 Full Synthetic, But Now I’m In The High Desert. Where It Can Reach Well Over 100 Degrees Fahrenheit. Also, 177,600 Miles With No Start Up Problems. From Time To Time I Do Smell Oil Burn-off. Can I Change Synthetic Motor Oil From 10W30 Too 10W40 Full Synthetic ?

[diyer2]

Yes

[It's Tim]

Complete waste of money...

Makes more sense to run dino and change it every 3K.

[pokismoki]

i ran the cheapest penzoil non synthetic for 30 years in my families old suburban, sold the truck with 320,000 miles, always changed it at 3k miles.  

for my LS motors, i use the  4000-4500 mile oil changes, and uses the cheap costco5-30w synth crap oil . 

[CamGTP]

Not sure if that was sarcasm or not.

 

10W30 and 10W40 costs the same and is barely anymore than conventional oil that is still a semi synthetic. We are talking like $5 if that because one brand of oil is always on sale where ever you go.

Edited April 11, 2022 by CamGTP

[Jsdirt]

I disagree, Tim. You can't beat the robust nature of certain brand synthetic's additive packages. They last longer, protect better, and flow better at all temperatures. It ends up cheaper to run synthetics longer and change them less frequently.

 

I spent the first 2 decades of my driving life changing oil at 3k miles. I'd never go back now.

Edited April 11, 2022 by Jsdirt

[Jsdirt]

3 minutes ago, pokismoki said:

i ran the cheapest penzoil non synthetic for 30 years in my families old suburban, sold the truck with 320,000 miles, always changed it at 3k miles.  

for my LS motors, i use the  4000-4500 mile oil changes, and uses the cheap costco5-30w synth crap oil . 

Something else you need to factor in - 30 years ago engines were built MUCH tougher than today's (2007-up) engines. Imagine how long those old engines would've lasted with synthetic oil from the get go! 

[It's Tim]

It takes a lot more than normal driving to cause a regular old dino oil to "fail". One changes the oil to get rid of the dirt and particulates that are suspended in the oil. 

 

 

[pokismoki]

15 minutes ago, Jsdirt said:

Something else you need to factor in - 30 years ago engines were built MUCH tougher than today's (2007-up) engines. Imagine how long those old engines would've lasted with synthetic oil from the get go! 

IDK these new LS motors can handle a burst power output of 1000 horse, if you can feed  air and fuel to them,. not sure the old 350  pushrod could do that..  now when you add on crap like vvt, and dod, yes the oil circuits need to have super clean oil that doesnt varnish up these delicate parts, hence why the need for synth and 4000 OCI

 

 

 

I have a chinese 4000watt harbor freight generator, it works great, and i used dyno oil in it when camping. 

then a few months later it wouldnt start, because the dyno oil varnished the exhaust valve and would get stuck in the valve guide, so i switched it to cheapo costco synth, guess what no more hung up exhaust valve, no varnish in the hot spots.. 

 

Edited April 11, 2022 by pokismoki

[Grumpy Bear]

10 minutes ago, Jsdirt said:

I disagree, Tim. You can't beat the robust nature of certain brand synthetic's additive packages. They last longer, protect better, and flow better at all temperatures. It ends up cheaper to run synthetics longer and change them less frequently.

 

Up until about 25 years ago I was part of the Kendal club. 2,000 mile OCI's like it was part of the ten commandments. Then I traded oils and methods. My current truck has been running pretty much Red Line HP on 5,000 mile OCI's since birth without issues. The wife's Terrain on Quaker State UD on the same intervals netted some huge ring sticking issues and one could conclude the oil failed to prevent the varnish that stuck them. UAO's told a different story. They showed a failed PCV system and a less than optimal tune although no misfire codes or MIL's ever tripped. Those issues are in process with great results. Almost 70 and I'm still in school. Recent lessons include but are not limited too:

 

1.) OCI is unit, operator and conditionally specific. (Burn that book and the OLM). 

2.) Detergent oils will NOT clean a dirty motor. They allow a motor in good tune to get dirty more slowly.  

3.) You can hide allot of issues with frequent oil changes. Could be cheaper to fix those issues. Maybe not. 

4.) Sometimes point #3 will be your best solution. When the fixes are not so cheap or not $$$$$ worth doing. 

5.) In the best of tune in the best of my motors, I've never seen ANY oil go past 7,500 miles without tapping out.

6.) FIND your OCI with VOA/UOA's and check now and again to assure. It's not a religion. It's a tool. 

7.) It's not Elfin magic. It's an education in reality that NEVER ends. 

 

 

 

 

 

 

[Jsdirt]

I ran Amsoil Signature Series 5w-30 for 9,985 miles of heavy towing and stop and go Northeastern madness. I sent in the oil analysis - I had high wear metals, but the oil TBN was still high, so that proves it wasn't the oil's failure that caused it. My theory is it's just the subpar parts GM sources from the lowest bidder, and the fact that 5w-30 is a bit thinner viscosity wise and thus offers less protection. When I switched to 10w-30 in the same oil, wear metal levels took a nosedive.

Recently I had an Amsoil EA oil filter plug up just shy of 7k miles, resulting in lower than normal oil pressure. If you look at oil filters on anything built in the 21st century, they're all the size of a friggin ATV or dirt bike oil filter! TINY! Way too small for the application. Manufacturers trying to save a buck again. The oil filter on our '93 940's little 2.3L 4-banger is 3x the size of what my Silverado runs! Apparently, the LS engines make a lot of trash that can stop up these tiny filters. The Amsoil EA-series filters down pretty tight - forgot how many microns, but it's MUCH less than anything sold in stores. That coupled with the tiny size is why they fill up so fast.

 

With our '93 Volvo 940, we run that same Signature Series 10w-30 for 15k miles. That's about when the Purolator Boss oil filter is about full anyway. That car has 114HP at the crank, so it's as weak as weak can be. They routinely last 300k-500k on the cheap stuff. It'll run 750k-1M miles on Amsoil. We're at 221k right now.

 

I ran dino in our Grand Marquis for 17 years. Engine was super dirty when I did the timing chain - only did that since I had to remove the cover to repair a big oil leak anyway. A couple years ago I switched to Pennzoil 10w-30 High Mileage synthetic. I'd run Amsoil in that, too, but she's had a rear main seal leak since we bought the car 19 years ago. About a quart every 1k miles. I never bothered to fix it, because everyone on the net said those AOD transmissions wouldn't last 1 mile over 100k. Well, we're at 287k and she's still truckin'! I'll fix it when the trans finally dies some day. 

[Grumpy Bear]

1 hour ago, Jsdirt said:

I ran Amsoil Signature Series 5w-30 for 9,985 miles of heavy towing and stop and go Northeastern madness. I sent in the oil analysis - I had high wear metals, but the oil TBN was still high, so that proves it wasn't the oil's failure that caused it.

 

TBN or Total Base Number is a measure of reserve alkalinity sir, not wear additive level. Just a reminder of what you already know. I do that all the time. 

[Jsdirt]

Well TBN is a good indicator of the health of the additive package. If the TBN number is low, you can bet the rest is junk, too. 

 

One of the best way to determine when to do the oil drain is to follow up with analyses, by measuring TAN and TBN.

 

https://www.rymax-lubricants.com/updates/total-base-number/

Edited April 12, 2022 by Jsdirt

[KARNUT]

I love it when some people say no oil is good past 7K miles. I can name 3 manufacturers that  have 10K oil changes, Honda, Toyota, VW. There also the longest lasting. I have two of those. I don’t do the 25K Amsoil oil changes anymore. I don’t run one vehicle that many miles per year anymore. I know high mileage drivers that still run high mileage oil changes with no complaints. I hate to break it to people everything wears out eventually. Most people aim for more bang for the buck. 3K oil changes with synthetic oil doesn’t achieve that goal. Waste of money. 

[diyer2]

I don't aim for more bang for the buck doing more frequent OCI's. I like clean, fresh oil. Simple. Worth the cost to me.