Oil consumption

Kelloggs67 · October 6, 2018

Just a reminder to Check you oil because Chevy says your allowed to burn 1 qt of oil every 2k

so if you stick to the Recommended oil change intervals through them you can burn 4 quarts of oil in between your oil changes your truck only holds 8qts

cr250Silverado · October 6, 2018

Wow, I’m not a mechanic but this seems to be un-reasonably high! I can only imagine the accelerated oil contamination and break down that occurs as the total volumne decreases.

Update; I found a FCA bulletin with the same burn rate...

maybe this is just the new standard they are taking to weasel out of warranty claims.

Edited October 6, 2018 by cr250Silverado

ftwhite · October 6, 2018

Thank for the reminder. Mine was indeed at the bottom of the stick.

300 Blackout · October 7, 2018

Thanks for the reminder.

Something that I didn’t know about until recently is the Noack Volatility Test which rates how much evaporation of oil you should expect at a constant temperature, airflow and time.

This is related to how much oil your engine will consume over a given period of time, use, etc... Every oil should have a Noack Volitility rating/value. The lower the number (% of loss by weight) the better and in thin oils like 0W-20 there can be significant variation. 15% loss is the maximum acceptable loss.

For example, Gulftec synthetic 0W-20 has 10.1% loss on the Noack and Amsoil Signature 0W-20 has 5.8% loss. You will consume nearly double the amount of Gulftec vs Amsoil under the same conditions.

Next time you’re shopping for oil, maybe take a look at the Noack and see if it effects how much oil you have to add in between changes.

71_340 · October 7, 2018

Every manufacturer usually states that oil consumption up tp quart every 1K miles is considered normal. If my truck would use that much it would be time for me to trade.

Grumpy Bear · October 7, 2018

Did you note that is says for trucks they are covered only if 'unloaded'? Really GM? If I use my truck to haul/tow I void my warranty?

gone_fishing · October 7, 2018

Has anyone experienced this much consumption? I burn around 1/2-3/4 of a quart between changes (usually around 7300 miles).

300 Blackout · October 7, 2018

Has anyone experienced this much consumption? I burn around 1/2-3/4 of a quart between changes (usually around 7300 miles).

Without any viscosity improvers, only burning 1/2-3/4 of a quart per 7300 miles is really good. What type of oil are you using?

pickmeup · October 7, 2018

I change my oil every 5,000 miles . Mobil 1 5-30 it uses maybe 4 ounces , virtually none.

Doublebase · October 7, 2018

10 hours ago, 300 Blackout said:

Thanks for the reminder.

Something that I didn’t know about until recently is the Noack Volatility Test which rates how much evaporation of oil you should expect at a constant temperature, airflow and time.

This is related to how much oil your engine will consume over a given period of time, use, etc... Every oil should have a Noack Volitility rating/value. The lower the number (% of loss by weight) the better and in thin oils like 0W-20 there can be significant variation. 15% loss is the maximum acceptable loss.

For example, Gulftec synthetic 0W-20 has 10.1% loss on the Noack and Amsoil Signature 0W-20 has 5.8% loss. You will consume nearly double the amount of Gulftec vs Amsoil under the same conditions.

Next time you’re shopping for oil, maybe take a look at the Noack and see if it effects how much oil you have to add in between changes.

Signature series I think does have a 6 rating in NOACK, which is excellent, but keep in mind you're talking about a $12 a quart oil = $96 dollar oil change, not including the filter.

Any Dexos approved oil has to have a NOACK bellow 13. Most name brand synthetic 0w20 oils are between 10-12.

I think direct injection engines are causing a lot of our oil to mist right through the PCV valve system. And I think fuel sprayed directly on the piston/cylinder walls is another part of the problem. I've read the fuel is mixing with the oil on the walls and actually igniting. I've also heard particulates are accumulating on piston ring lands, causing the rings to become "stuck", which is leading to too much consumption and blowby. I've heard the rings are in worse shape than in Diesel engines.

I'll be monitoring my Silverado closely - right now I'm only burning a half a quart between 5,000 mile intervals - but I have personally seen Silverados burning three quarts between 5,000 mile changes. I have already dealt with excessive oil consumption in my previous direct injected vehicle (Lexus LS 460). It began using a quart every 1,000 miles. And I took damn good care of that car - I was absolutely anal with maintenance - and I babied that thing like you wouldn't believe. No car on the road had an easier highway commute.

Doublebase · October 7, 2018

8 hours ago, gone_fishing said:

Has anyone experienced this much consumption? I burn around 1/2-3/4 of a quart between changes (usually around 7300 miles).

I'm burning around a half a quart in 5,000 miles, so I'd say you're doing excellent. Plus my truck only has 15,000 miles on it.

This light weight oil is doing no favors to engines and oil consumption nowadays. I wish they'd design an engine that uses 5w30 again, and still manage to get under their CAFE regulations. I probably will switch to 5w30 eventually but I worry about variable valve timing and the AFM system and how it uses the oil to activate those systems.

Edited October 7, 2018 by Doublebase

KARNUT · October 7, 2018

I’ve only had two newer vehicles use oil 94 Z-28, 99 Ford p/u. They both use 1 qt every 2500 miles. The Ford had a blower installed never change the usage. Most of my vehicles were extended drain since the 90s.

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300 Blackout · October 7, 2018

Signature series I think does have a 6 rating in NOACK, which is excellent, but keep in mind you're talking about a $12 a quart oil = $96 dollar oil change, not including the filter.

Any Dexos approved oil has to have a NOACK bellow 13. Most name brand synthetic 0w20 oils are between 10-12.

Thanks for the info about the Dexos spec.

Yep, AMSOIL is pricey stuff. If, however, you can get 25k miles between oil changes with it, then it’s less expensive than lower priced quality options requiring changes every 7,500 miles. Right now I run Valvoline High Mileage full synthetic, which is also excellent oil. The Valvoline, however, has a NOACK of 11.1 and a reputation for higher consumption.

I’m installing a bypass oil filter next week. If the Valvoline exhibits lower consumption with the better filtration, great. If not, I’m gonna try the Amsoil and see how far it will go.

gone_fishing · October 7, 2018

14 hours ago, 300 Blackout said:

Without any viscosity improvers, only burning 1/2-3/4 of a quart per 7300 miles is really good. What type of oil are you using?

Been on a pretty steady diet of Mobil 1 0W-20. I currently have 142,000 miles on my Sierra and AFM has been disabled since around 90,000 miles. I really didn't notice much difference in oil consumption after disabling AFM. I'm now on my 2nd OCI with Mobil 1 5W-30. Consumption seems to be about the same.

Grumpy Bear · October 7, 2018

I change every 5,000 miles. Have 78,000 on her and have never used a drop of oil and have had three different oils in service over that time. Lost count of how many vehicles I've owned and have exactly two that used any measurable amount. A 64 Malibu 283 I bought with about 150,000 already on it and a new Toyota Peso I used an early Pennzoil semi synthetic blend product in. I tried 7,500 mile oil changes. Still ran 300,000 miles. (Before the Shell buyout). Thing was ugly inside when opened up. Unlike any motor I had ever cracked open.