Shorten OCI w/ ethanol usage? 2014 GM L83 5.3

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My 2014 Chevrolet Silverado has the 5.3 L83 engine and I use E85 exclusively. I am almost 2,000 miles into my OCI and the OLM is tracking precisely towards the 7,500 mile OCI that GM recommends.

Ford calls for a severe service OCI when using E85 (according to my previous 2009 FX4). GM doesn't even mention a shortened OCI (for any reason) anywhere that I have found yet for this engine. I thought that GM might have the PCM programmed to shorten the OCI with E85 usage and other factors but she is on track to hit 7,500 miles almost exactly at 0%.

I am running Mobil 1 EP 0w20 w/ Wix 57045 and am planning on an OCI at 3,000 just to see if the E85 is chewing up the oil and see if I have any dilution due to the direct injection.

Thoughts?
 
Flex Fuel engine ?

How does fuel economy on E85 compare to the E10 common here ?

Thanks , :)
Wyr
God bless
 
Originally Posted By: WyrTwister
Flex Fuel engine ?

How does fuel economy on E85 compare to the E10 common here ?

Thanks , :)
Wyr
God bless


20/25% less mpg. I just run regular pump gas. I've never found an e85 station to be convenient in terms of location. I few tanks of e85 will clean out a motor though. Carbon go bye bye. Also the motor is supposed to add 10HP on e85. I guess ford programmed it to advance the timing
 
For my Toyota flex-fuel vehicle, the OCI is one half that of the regular fuel vehicles.

For my truck, the OCI is 10,000 miles for a regular engine, it's 5,000 miles for the flex fuel.

The service minder in my Tundra (an FFV) is simply set to 5,000 miles. No real OLM that monitors usage. It simply counts down time and miles. Interestingly, the owner's manual goes on to say that if primarily E85 fuel is used, the oil change interval should be halved, which implies a 2,500 mile OCI...

As far as MPG, arithmetic would tell you that 85% ethanol would get you about a 35% loss in MPG, because of energy density of ethanol versus gasoline.

In practice, it's closer to 20% loss in MPG.

This may be because E85 is anywhere from 50% to 85% ethanol, so the full reduction isn't realized because it's not actually 85% ethanol every time I've filled it. Further, the truck runs better on E85. More responsive, more HP. Not a huge change, but definitely noticeable. So, perhaps I am also using less throttle, which might contribute to efficiency in a very modest way.
 
Your Silverado has an OLM, which will account for the E85 usage
smile.gif
 
Originally Posted By: WyrTwister
Flex Fuel engine ?

How does fuel economy on E85 compare to the E10 common here ?

Thanks , :)
Wyr
God bless


https://bobistheoilguy.com/forums/ubbthr..._oc#Post4392091


Originally Posted By: CT8
Syn oil seems like a 100% waste with short oil changes.


GM only allows for 0w20 in this engine and I have a factory 100,000 mile powertrain warranty to maintain.


Originally Posted By: slacktide_bitog
Your Silverado has an OLM, which will account for the E85 usage
smile.gif



That is just it, the OLM hasn't reduced oil life beyond 7,500 miles per OCI. The OLM shows a percentage and when you do the math of miles driven versus percentage used it works out to almost exactly 7,500 miles - as in 7,4XX. It would appear that the OLM is just a counter and not a 'smart' OLM.
 
My 2013 Ford doesn't say anything about a shorter OCI. It does say to run a tank of regular gas each oil change if using e85 exclusively.
 
My wife has a 2012 Grand Caravan with the 3.6L Pentastar. It goes from 17-18 mpg on E10 to around 14-15 mpg on E85. I have a few E85 stations close by, but the price usually isn't worth it. However, it hit $1.50 last week, so I filled it up. There's definitely more torque and HP. I changed the plugs last month, and the valves were very clean. I'd been using E85 every few tanks.
 
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Originally Posted By: 04SE
My 2014 Chevrolet Silverado has the 5.3 L83 engine and I use E85 exclusively. I am almost 2,000 miles into my OCI and the OLM is tracking precisely towards the 7,500 mile OCI that GM recommends.

Ford calls for a severe service OCI when using E85 (according to my previous 2009 FX4). GM doesn't even mention a shortened OCI (for any reason) anywhere that I have found yet for this engine. I thought that GM might have the PCM programmed to shorten the OCI with E85 usage and other factors but she is on track to hit 7,500 miles almost exactly at 0%.

I am running Mobil 1 EP 0w20 w/ Wix 57045 and am planning on an OCI at 3,000 just to see if the E85 is chewing up the oil and see if I have any dilution due to the direct injection.

Thoughts?


Your Oil Life Monitor will account for the E85 automatically and shorten your OCI accordingly. Watch how quickly your oil life drops while running E85.
 
Originally Posted By: SilverFusion2010
Originally Posted By: WyrTwister
Flex Fuel engine ?

How does fuel economy on E85 compare to the E10 common here ?

Thanks , :)
Wyr
God bless


20/25% less mpg. I just run regular pump gas. I've never found an e85 station to be convenient in terms of location. I few tanks of e85 will clean out a motor though. Carbon go bye bye. Also the motor is supposed to add 10HP on e85. I guess ford programmed it to advance the timing



20% - 25% Is about what I have heard . Do not have a flex fuel vehicle , but with the decreased mileage , the cheaper price for E85 seems like just about a wash ? ( There is a convenience store close to work that has E85 . )

Thanks ! :)

Wyr
God bless
 
I concluded that it was a wash the last time I crunched numbers but it's been years since I seriously looked at it. If you care about using less gasoline then that's a point to consider. Otherwise I think it's kind of a fools fuel. I wish I could find E0 at a reasonable price
 
E85 can pollute sumps, especially in cold start conditions where the fuel mix is rich and no parts are yet at operating temperature (the same is true of normal petrol.) However ethanol poorly mixes with oil - hence potential for problems. Thus, if you only do short trips as part of your regular commute (say live in the mountains / sports driving / ...) then the more volatile petrol and ethanol will vaporise and be consumed through your engines crank case breathing system.

Remember ethanol has a boiling point of 78C, while engine oil is supposed to operate at 100C. Petrol likewise has a boiling point far below 100C, though this will vary from region to region / month to month.

Ford have had similar sump pollution problems in their passenger diesels with DPF's. The 'active' regen dumps significant amounts of fuel into the engine to 'burn-off' soot in the filter. However, this causes the cylinder bores to be washed and fuel escapes into the sump. Overtime this excess fuel vaporises.

In theory, engines that burn alcohol fuels 'should' keep their engine oils cleaner though significantly lower soot production. It's just that in certain use cases, oil can become contaminated. And unlike the diesel example, petrol and ethanol have no lubricity. Hence the valid concern.

For the cost of an oil change and if you're curious, it would be good to know the results. But GM gave a warrenty based on their engineering and testing, suggesting 7,500miles.

Regards
Jordan.
 
Just because a vehicle is E85 compatible doesn't mean the OLM assumes you are running it - at least I don't think so. Change your oil twice as often as when you're running E10. OLM at 50% life = change now. E85 is a waste of time unless you're forced to use it by your company in their vehicle.
 
Originally Posted By: bigt61
Just because a vehicle is E85 compatible doesn't mean the OLM assumes you are running it - at least I don't think so. Change your oil twice as often as when you're running E10. OLM at 50% life = change now.


It does on GMs OLM. The 5.3 make 355/383 on pump gas but 380/416 on E85. Those are official numbers from GM after the ECU accounts for the ethanol content. GM owners manuals say nothing about E85 oil life intervals because its already baked into the OLM algorithms.

Originally Posted By: bigt61
E85 is a waste of time unless you're forced to use it by your company in their vehicle.


Lingenfelter Performance ran a bone stock 2014 Silverado on the dyno and saw +14hp/23tq at the wheels gain. They ran it down the quarter and shaved almost half a second off the 0-60 and the 1/4 mile. Maybe a waste from an efficiency standpoint, but it makes power. Can't deny that. At least in the truck in question it does.
 
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Originally Posted By: zuluplus30
... Those are official numbers from GM after the ECU accounts for the ethanol content. ...


How does it do this? Through oxygen sensor data? I am still curious.
 
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