2.0 NA gas spec

happycamper515

Senior Member
Joined
Sep 7, 2020
Threads
15
Messages
56
Reaction score
25
Location
Hawaii
Vehicle(s)
Lexus
Country flag
Anyone with the 2.0 NA engine running 91 octane gas? Was there a noticeable difference going from 87 to 91?
Sponsored

 

bcrichster

Senior Member
First Name
Wes
Joined
Apr 20, 2020
Threads
2
Messages
466
Reaction score
244
Location
FL
Vehicle(s)
2020 Civic Sport 2.0L, 1998 Civic LX D16-MiniMe
Country flag
Umm.. no
Anyone with the 2.0 NA engine running 91 octane gas? Was there a noticeable difference going from 87 to 91?
I do use 89 E-Free, really seem to get slightly better ga$ mileages and takeoff than regular 87 & reg 89 (butt dyno, honestly.. no real data besides the ga$ mileages).
 
OP
OP

happycamper515

Senior Member
Joined
Sep 7, 2020
Threads
15
Messages
56
Reaction score
25
Location
Hawaii
Vehicle(s)
Lexus
Country flag
I'm a little surprised at my MPG. I only have about 100 miles on the car and dash info says 22.5 MPG. About half of that has been freeway driving and the other half city driving with about 30 minutes of stop and go traffic.
 

BrandonSmith

Senior Member
Joined
Oct 20, 2020
Threads
14
Messages
847
Reaction score
756
Location
The Greatest Country on Earth
Vehicle(s)
2016 Civic EX 2.0L
Country flag
I’ve never gotten lower than 30 mpg on a full tank in my 100k miles of driving this car. The one time I did was all city driving in Texas winter. Generally never get below 32-33 mpg per tank mixed city/hwy.

I’ve run mid grade and premium at times on 1000 mile, one-day runs and have noticed minimal difference (if any) in mpg: rightfully so as the engine is designed for 87. The biggest difference for me has been running ethanol-free fuel. It’s normally a 2 mpg increase on a tank.
 
OP
OP

happycamper515

Senior Member
Joined
Sep 7, 2020
Threads
15
Messages
56
Reaction score
25
Location
Hawaii
Vehicle(s)
Lexus
Country flag
When I'm on the freeway that live MPG bar shows I'm getting 60+ MPG so I would think that offsets those periods of stop and go traffic. And I've been short shifting keepings RPMs below 3,000 while I break in the car. I'll try 91 octane on the next tank.
 


NonyaBisness

Senior Member
Joined
Dec 5, 2019
Threads
13
Messages
290
Reaction score
188
Location
United States
Vehicle(s)
2016 Civic EX-T
Country flag
Anyone with the 2.0 NA engine running 91 octane gas? Was there a noticeable difference going from 87 to 91?
NO, you won't notice a difference other then your wallet bieng lighter.

Umm.. no
I do use 89 E-Free, really seem to get slightly better ga$ mileages and takeoff than regular 87 & reg 89 (butt dyno, honestly.. no real data besides the ga$ mileages).
And with good reason, Ethanol is less energy dense then gasoline (see the section about Fuel Properties) https://afdc.energy.gov/fuels/ethanol_fuel_basics.html so with Ethanol having 30% lower energy density and accounting for up to 10% of the fuel mix in regular gasoline you must mathematically get lower fuel mileage (probably not more then 3% if my math is accurate), based on simple science. The question becomes is the increase in fuel mileage enough to justify the added cost of Ethanol Free Gas, for me it's NOT. I generally only run (or ran) Ethanol Free in older Pre 2000's cars as the Ethanol loves to eat teh seals in older fuel systems, once ethanol mix fuels became the standard car manufactures changed up materials.
 

Romeoridgee

Honda Dealer Tech.
First Name
Rob
Joined
Mar 7, 2019
Threads
36
Messages
1,790
Reaction score
821
Location
Maryland
Vehicle(s)
19 SPT 17 EX-T 08 LX 21 CRV 12 Acc 14 328I CONV
Vehicle Showcase
1
Country flag
Higher octane fuel only increases knock resistance. The pcm determines the octane with knock sensor and timing advances. Higher octane = more timing. I only put 93 in mine, when I first did it I noticed a VERY small difference in power. The highest economy I’ve gotten on 93 was 43mpg and that was keeping the bar above 40mpg and not going over 60...
 

David Harper

Senior Member
Joined
Apr 28, 2016
Threads
64
Messages
884
Reaction score
420
Location
Crystal Lake, Il.
Vehicle(s)
2016 Civic coupe
Country flag
NO, you won't notice a difference other then your wallet bieng lighter.



And with good reason, Ethanol is less energy dense then gasoline (see the section about Fuel Properties) https://afdc.energy.gov/fuels/ethanol_fuel_basics.html so with Ethanol having 30% lower energy density and accounting for up to 10% of the fuel mix in regular gasoline you must mathematically get lower fuel mileage (probably not more then 3% if my math is accurate), based on simple science. The question becomes is the increase in fuel mileage enough to justify the added cost of Ethanol Free Gas, for me it's NOT. I generally only run (or ran) Ethanol Free in older Pre 2000's cars as the Ethanol loves to eat teh seals in older fuel systems, once ethanol mix fuels became the standard car manufactures changed up materials.
exactly. premium fuel is not 'better' than regular. In absolute terms, it's actually worse. It retards combustion in order to avoid pre-ignition knock. But you will experience the enjoyment of paying more. Also ethanol does have a benefit; it dissolves into solution water and water-based contaminants so that they never accumulate at the bottom of your gas tank.
 

fjrman

Senior Member
Joined
Feb 12, 2017
Threads
13
Messages
335
Reaction score
151
Location
Tennessee
Vehicle(s)
2016 Civic 4 door LX with CVT
Country flag
Happycamper, why don't you try a tank of 91 and tell us what you experienced!
 

Romeoridgee

Honda Dealer Tech.
First Name
Rob
Joined
Mar 7, 2019
Threads
36
Messages
1,790
Reaction score
821
Location
Maryland
Vehicle(s)
19 SPT 17 EX-T 08 LX 21 CRV 12 Acc 14 328I CONV
Vehicle Showcase
1
Country flag
exactly. premium fuel is not 'better' than regular. In absolute terms, it's actually worse. It retards combustion in order to avoid pre-ignition knock. But you will experience the enjoyment of paying more. Also ethanol does have a benefit; it dissolves into solution water and water-based contaminants so that they never accumulate at the bottom of your gas tank.
If we are comparing octane with the same content ethanol (10%) in pump gas stations, you are half right. If a car is designed to run 93 from the factory, and you put 87 in, then timing is retarded because of excess misfires. Higher octane in a car that’s designed for low octane will not retard the flame front, it allows for higher potential maximum cylinder pressure, so you could either change compression ratio, timing, or add boost (very minuscule). The only downside to running 93 is more money, but comes with peace of mind. Remember I’m not talking about changing ethanol content. That’s an area I haven’t mastered yet since I’ve yet to experiment with e85, but soon to come I will.
 


David Harper

Senior Member
Joined
Apr 28, 2016
Threads
64
Messages
884
Reaction score
420
Location
Crystal Lake, Il.
Vehicle(s)
2016 Civic coupe
Country flag
If we are comparing octane with the same content ethanol (10%) in pump gas stations, you are half right. If a car is designed to run 93 from the factory, and you put 87 in, then timing is retarded because of excess misfires. Higher octane in a car that’s designed for low octane will not retard the flame front, it allows for higher potential maximum cylinder pressure, so you could either change compression ratio, timing, or add boost (very minuscule). The only downside to running 93 is more money, but comes with peace of mind. Remember I’m not talking about changing ethanol content. That’s an area I haven’t mastered yet since I’ve yet to experiment with e85, but soon to come I will.
I believe that the way premium allows for higher potential maximum cylinder pressure is by delaying ,in effect, combustion so that it doesn't take place before it's supposed to. This is accomplished by making the fuel-air mixture less combustible. In and of itself this does not make the fuel "more powerful", it only allows for higher compression in the chamber before combustion. It is this higher compression ratio which results in more horsepower being produced, not the fuel itself. Ounce for ounce regular gas packs more of a wallop than premium because it contains more potential energy. The additive in premium fuel reduces the potential energy produced. If you put regular into a car that calls for premium it ignites and combusts too early, before the spark plug fires , because of the greater heat and pressure in the combustion chamber. If you put premium into a car that calls for regular you accomplish absolutely nothing. Any increase in power that you think you feel is the placebo effect. Nor is there any increase in gas mileage.
To counteract premature combustion premium fuel is made less combustible than regular. And it contains less potential energy, not more.
 
Last edited:

redcoats1976

Senior Member
First Name
jim
Joined
May 17, 2020
Threads
14
Messages
270
Reaction score
204
Location
central florida
Vehicle(s)
2018 civic coupe,2015 camaro RS
Country flag
i have always used 89,highest mileage was 43-44(!!!)but the average is around 32.the 43-44 was on a long trip through the middle of nowhere ,eco button on and not driving more than 65 mph.
 


 


Top