Winter gas stinks - before and after datalogs adding 2 gal of Sheetz E85

[TiGeo]

Amazing what a splash of E85 does with winter blend 93 here in VA in my car - mixed 2 gal Sheetz E85 with my 14.5 gal tank for ~E20. Peak ignition advance to ~8.5 degrees at redline in third up from 6 on 93 (E10). Knock all over on 93 (but no driveability issues) to nearly zero on the E20 blend. My logs on summer 93 look fine with minor knock correction and higher advance like I'm seeing here on winter with the E added. The car/tune handles the 20% without issue. Fuel pressure etc. all look fine. I hate winter gas...the cold temps for max power but crappy fuel. These are gear 2-4 logs from a rolling start, I back off once I hit 100mph.

Winter 93 only (E10). Lots of feedback on the knock sensors. Peak advance in third gear (that's the center of the graph) to ~6 deg.

Added 2 gal of E85 to my tank and covered with the balance 93 E10. E20. Drove a bit. Log after. Some minor knock sensor feedback in second then gone. Advance up to ~8.5 deg up from 6. That's added POWA baby!

Links to logs...you can toggle on/off all the various logging parameters:

https://datazap.me/u/karstgeo72/gsw-23?log=0&data=5-11-19

https://datazap.me/u/karstgeo72/gsw-22?log=0&data=5-11-19

 

[fantastic]

Amazing that 93 E10 alone doesn't get you the same or better results. I've contemplated putting a small amount of E85 in the Volvo but I don't think I want any trouble. I do use 88 E15 though most of the time. Thanks for showing us a before & after. Will you try summer blend version of this test?

 

[TiGeo]

Amazing that 93 E10 alone doesn't get you the same or better results. I've contemplated putting a small amount of E85 in the Volvo but I don't think I want any trouble. I do use 88 E15 though most of the time. Thanks for showing us a before & after. Will you try summer blend version of this test?

The simple issue is the tune is calibrated on a better fuel than our winter 93 - winter fuels detonate easier. The ECU handles this for you you just don't make quite as much power...it's likely a wash b/c you also are making more than in summer based solely on the lower DA/colder temps. 93 E10 is the normal fuel about everywhere so not sure what you mean by 93 E10 doing better? What are you trying to achieve running anymore E than regular gas has in it in your Volvo.

Summer 93 (all gas here is E10) log. Minor knock in third (less than the E20 with winter 93), timing advanced out to 7 and change deg, so actually a touch less than the winter E20 log.

https://datazap.me/u/karstgeo72/gsw-21?log=0&data=5-11-19-22-23-24-25&zoom=1689-1955

 

[The_Jeff]

What is this mechanism where winter fuels detonate easier? I've noticed it myself, typically on an unseasonably warm March day. Haven't heard much about it otherwise.

 

[TiGeo]

What is this mechanism where winter fuels detonate easier? I've noticed it myself, typically on an unseasonably warm March day. Haven't heard much about it otherwise.

Winter gas has a higher vapor pressure meaning it evaporates more easily. It contains butane. This helps engines start and run smoothly in cold temperatures because the fuel vaporizes easily helping combustion. This is what is causing the increased detonation...basically it combusts easier.

 

[fantastic]

The simple issue is the tune is calibrated on a better fuel than our winter 93 - winter fuels detonate easier. The ECU handles this for you you just don't make quite as much power...it's likely a wash b/c you also are making more than in summer based solely on the lower DA/colder temps. 93 E10 is the normal fuel about everywhere so not sure what you mean by 93 E10 doing better?

I guess what I'm saying is that you'd think the 93 E10 alone would provide max power from your engine (No E85). E20 increases the octane for more power is what I'm collecting you're saying?

What are you trying to achieve running anymore E than regular gas has in it in your Volvo.

The XC90 recommends 91 octane for best performance. Get my whole whopping 235 HP...ha! I figure adding some more Ethanol (E85) to my 88 would get me the rated horsepower. Possibly not the rated fuel economy though since it's higher in ethanol than straight 91 E10.

My biggest curiosity is finding out if E85 is really 85% ethanol throughout the year or how it fluctuates. I need to go dig some more. I thought I'd read it may be a range like summer vs winter as well.

 

[TiGeo]

I guess what I'm saying is that you'd think the 93 E10 alone would provide max power from your engine (No E85). E20 increases the octane for more power is what I'm collecting you're saying?

The XC90 recommends 91 octane for best performance. Get my whole whopping 235 HP...ha! I figure adding some more Ethanol (E85) to my 88 would get me the rated horsepower. Possibly not the rated fuel economy though since it's higher in ethanol than straight 91 E10.

My biggest curiosity is finding out if E85 is really 85% ethanol throughout the year or how it fluctuates. I need to go dig some more. I thought I'd read it may be a range like summer vs winter as well.

It does...when it's summer 93 E10. It's winter, the 93 E10 detonates easier even with teh same octane rating per the comments I made above to another poster so adding the splash of E85 effectively raises the octane back up to what the summer gas gives you in terms of performance. You don't need it, but it helps optimize power. Remember, my car is tuned and when you tune it, one of the largest variables is fuel quality. It's why custom tuning is nice, you can have two different tunes...one for summer, one for winter...I don't have that ability with my canned/OTS tune.

I have tested the E85 at our local Sheetz(s) and found it's about bang on, slightly less in winter.

For you, you'd need to log your car to know if running higher octane fuel is really doing anything.

 

[CDNozzle]

Very interesting @TiGeo .
But allow me to nitpick on the lingo used here.

Detonation is a different mode of combustion that happens extremely fast (supersonic flamefront), causes a sharp pressure rise, and will destroy your engine if it actually operated on detonation every cycle.

Deflagration is what you really mean (subsonic combustion).

 

[TiGeo]

Very interesting @TiGeo .
But allow me to nitpick on the lingo used here.

Detonation is a different mode of combustion that happens extremely fast (supersonic flamefront), causes a sharp pressure rise, and will destroy your engine if it actually operated on detonation every cycle.

Deflagration is what you really mean (subsonic combustion).

I have never head anyone refer to common knock as "deflagration" - always det. Pre-ignition is when the fuel/air combusts before the spark fires. Detonation is common knock that involves multiple wave fronts after the plug goes. How I always have understood it.

 

[fantastic]

It does...when it's summer 93 E10. It's winter, the 93 E10 detonates easier even with teh same octane rating per the comments I made above to another poster so adding the splash of E85 effectively raises the octane back up to what the summer gas gives you in terms of performance. You don't need it, but it helps optimize power. Remember, my car is tuned and when you tune it, one of the largest variables is fuel quality. It's why custom tuning is nice, you can have two different tunes...one for summer, one for winter...I don't have that ability with my canned/OTS tune.

I have tested the E85 at our local Sheetz(s) and found it's about bang on, slightly less in winter.

For you, you'd need to log your car to know if running higher octane fuel is really doing anything.

Ah, I understand what you're saying now. Thanks for the explanation.

 

[Kernel Potter]

quote:
TiGeo
"Amazing what a splash of E85 does with winter blend 93 here in VA in my car - mixed 2 gal Sheetz E85 with my 14.5 gal tank for ~E20. Peak ignition advance to ~8.5 degrees at redline in third up from 6 on 93 (E10). Knock all over on 93 (but no driveability issues) to nearly zero on the E20 blend. My logs on summer 93 look fine with minor knock correction and higher advance like I'm seeing here on winter with the E added. The car/tune handles the 20% without issue. Fuel pressure etc. all look fine. I hate winter gas...the cold temps for max power but crappy fuel. These are gear 2-4 logs from a rolling start, I back off once I hit 100mph."


Since mine isn't tuned I can get away on 87 octane with 2 to 3 gallons of E85 in a 14.7 gallon tank. GM recommends 91 but says 87 is the minimum. It does have 10:1 compression and 15 lbs of boost.

With the E85 in the mix, to me, it mimmicks a mild tune by seat-of-the-pants feel. So getting between 37 and 41 mpg per tank with a 90 to 91 octane blend for about $2.75 a gallon is a winner to me.

 

[CDNozzle]

I have never head anyone refer to common knock as "deflagration" - always det. Pre-ignition is when the fuel/air combusts before the spark fires. Detonation is common knock that involves multiple wave fronts after the plug goes. How I always have understood it.

Agreed that knock is detonation, but the below quotes appear to me that some are referring to the act of combustion in general as detonation. I'm just saying that the correct terms should be used so to not confuse.

What is this mechanism where winter fuels detonate easier? I've noticed it myself, typically on an unseasonably warm March day. Haven't heard much about it otherwise.

Winter gas has a higher vapor pressure meaning it evaporates more easily. It contains butane. This helps engines start and run smoothly in cold temperatures because the fuel vaporizes easily helping combustion. This is what is causing the increased detonation...basically it combusts easier.

 

[TiGeo]

Agreed that knock is detonation, but the below quotes appear to me that some are referring to the act of combustion in general as detonation. I'm just saying that the correct terms should be used so to not confuse.

Both of those are not refering to standard combustion as detonation, det here is det...spark knock in this thread.

 

[TiGeo]

quote:
TiGeo
"Amazing what a splash of E85 does with winter blend 93 here in VA in my car - mixed 2 gal Sheetz E85 with my 14.5 gal tank for ~E20. Peak ignition advance to ~8.5 degrees at redline in third up from 6 on 93 (E10). Knock all over on 93 (but no driveability issues) to nearly zero on the E20 blend. My logs on summer 93 look fine with minor knock correction and higher advance like I'm seeing here on winter with the E added. The car/tune handles the 20% without issue. Fuel pressure etc. all look fine. I hate winter gas...the cold temps for max power but crappy fuel. These are gear 2-4 logs from a rolling start, I back off once I hit 100mph."


Since mine isn't tuned I can get away on 87 octane with 2 to 3 gallons of E85 in a 14.7 gallon tank. GM recommends 91 but says 87 is the minimum. It does have 10:1 compression and 15 lbs of boost.

With the E85 in the mix, to me, it mimmicks a mild tune by seat-of-the-pants feel. So getting between 37 and 41 mpg per tank with a 90 to 91 octane blend for about $2.75 a gallon is a winner to me.

E85 is amazing stuff. I'm suprised they don't sell it at the race tracks...so many cars tune for it now b/c it's easy power.

 

[gamefoo21]

I guess what I'm saying is that you'd think the 93 E10 alone would provide max power from your engine (No E85). E20 increases the octane for more power is what I'm collecting you're saying?

The XC90 recommends 91 octane for best performance. Get my whole whopping 235 HP...ha! I figure adding some more Ethanol (E85) to my 88 would get me the rated horsepower. Possibly not the rated fuel economy though since it's higher in ethanol than straight 91 E10.

My biggest curiosity is finding out if E85 is really 85% ethanol throughout the year or how it fluctuates. I need to go dig some more. I thought I'd read it may be a range like summer vs winter as well.

View attachment 305992

The 3.2 is really not very picky, at least mine isn't, tested 87, 89 and 91 in the hills... There's almost zero difference in the hills between 89 and 91. I know the hills well, I set the cruise and I just let it drive, and it'll downshift if the knock sensors get tickled.

The 4.4L in our new to us XC90, specifically says 87 is only for emergency use as it can damage the engine... lol

 

[fantastic]

The 3.2 is really not very picky, at least mine isn't, tested 87, 89 and 91 in the hills... There's almost zero difference in the hills between 89 and 91. I know the hills well, I set the cruise and I just let it drive, and it'll downshift if the knock sensors get tickled.

Same, I've run 88 e15 mainly but I've never tried 91 or higher.

The 4.4L in our new to us XC90, specifically says 87 is only for emergency use as it can damage the engine... lol

Seems straight to the point...Ha! That is interesting about that Yamaha V8 engine.

 

[Japanese]

The simple issue is the tune is calibrated on a better fuel than our winter 93 - winter fuels detonate easier.

Why do you think there is a difference b/w summer and winter 93 gasoline? And what that would be?

The only difference might be that you mix your fuel with E85 and the ethanol doesn't work well in the winter and ecpecially below 32*F.
I wouldn't use E85 in the winter.

 

[TiGeo]

Why do you think there is a difference b/w summer and winter 93 gasoline? And what that would be?

The only difference might be that you mix your fuel with E85 and the ethanol doesn't work well in the winter and ecpecially below 32*F.
I wouldn't use E85 in the winter.

Time to read through the thread, all explained.

 

[Kernel Potter]

Why do you think there is a difference b/w summer and winter 93 gasoline? And what that would be?

The only difference might be that you mix your fuel with E85 and the ethanol doesn't work well in the winter and ecpecially below 32*F.
I wouldn't use E85 in the winter.

In the hottest months I'll put about 3 gallons of E85 per tank. In the coldest months I'll back it off to about 1 gallon, which considering by dec/jan the E85 will be closer to E51. So about a gallon and a half goes in so I can at least have an E15 blend, give or take. THe amount is about 2 gallons inbetween the temperature extremes.

When I first acquired the car the spread of 87 and 93 fluctuated between 30 and 60 cents - I'd just put in the 93. But then big oil got super greedy and it became about 90 cents. Then a buck to a buck fifteen. Shell stations especially, are often more than that.

The supply and demand curve broke. I found a great solution.

 

[SumGuy]

I'm a bit confused with the numbers here. Comparing E85 with E10, given they're the same octane, can you advance your ignition more with E85?

I see the advance numbers posted here in a range of up to 10 degrees. Is that total (actual) degrees BTDC? That doesn't sound like much. I'd expect that number to be 30 - 40 degrees at highway cruise (say 2500 rpm for an old V8 with highway gears).

Are ignition advance timing numbers (degrees BTDC) comparable between a 4 cyl and 8 cyl if all else is equal (same comp ratio, same gasoline, same octane)? I'm talking max advance without detonation (pinging).