93 octane in a 2007 Honda Civic

[SandEagle]

worth it?

 

[Throckmorton]

What does the manual say?

 

[satyajitmenon]

Not without a remap or something to change timing, etc. Stock car - don't see the point.

 

[JTsyo]

Not without a remap or something to change timing, etc. Stock car - don't see the point.

this, it's not designed for that fuel.

 

[JCH13]

Not from a performance standpoint.

 

[Dirigible]

It will effectively remove some of that annoying excess money you've got.

Go for it!

 

[996GT2]

Is it a Civic SI? Does it have a turbo?

If no to the above 2 questions, then using 93 octane is about the same as flushing some dollar bills down the toilet

 

[yottabit]

If it's an Si, certainly

Otherwise, no.

Unless the manual calls out for it or the engine is for some reason knocking, there is ALMOST never any benefit to running a higher grade of fuel than required

Octane is strictly a measure of knock resistance.

 

[exar333]

If it's an Si, certainly
Otherwise, no.

Unless the manual calls out for it or the engine is for some reason knocking, there is ALMOST never any benefit to running a higher grade of fuel than required

Octane is strictly a measure of knock resistance.

Why? The Si has not need for anything higher than low-grade fuel. Even 91 is more than you need and is wasting $$$.

 

[chin311]

I thought SI's wanted premium?

 

[Blain]

Haters are gonna hate! We can't stop them.

Run that 93 octane, knowing you're burning the best gas in town.

 

[yottabit]

Why? The Si has not need for anything higher than low-grade fuel. Even 91 is more than you need and is wasting $$$.

except for the sharp decrease in fuel economy and dramatic loss of power you'll get by running a k20 on 87 octane. 11:1 compression ratio engine...

 

[996GT2]

Why? The Si has not need for anything higher than low-grade fuel. Even 91 is more than you need and is wasting $$$.

K20Z3
This inline-4 cylinder internal combustion engine is found in the US market Honda Civic Si (2006+) & Canadian market Acura CSX Type-S. It has an aluminum block with an aluminum head, and a bore and stroke of 86 mm x 86 mm, resulting in a 1,998 cc (121.9 cu in) displacement.

Displacement : 1,998 cc (121.9 cu in)
Compression : 11:1
Power: 197 bhp (147 kW) @ 7800 rpm (sae NET Rev 8/04)
Torque: 140 ft·lbf (189 N·m) @ 6200 rpm (sae NET Rev 8/04)
Redline: 8000 rpm
Fuel Cutoff: 8200 rpm
i-VTEC Engagement Window:5800 rpm

Yeah, that's gonna need premium

 

[mmntech]

I've been told that running high octane will clean gunk out by a mechanic, if you run the crap out of the engine. Even then, only once in a blue moon. Not sure how true that is though.

 

[MrWizzard]

Stock car - don't see the point.

99% true. OP stick to 91.

 

[overst33r]

I've been told that running high octane will clean gunk out by a mechanic, if you run the crap out of the engine. Even then, only once in a blue moon. Not sure how true that is though.

It will do that on any grade fuel. One redline a day keeps the mechanic away. :sneaky:

 

[LTC8K6]

I've been told that running high octane will clean gunk out by a mechanic, if you run the crap out of the engine. Even then, only once in a blue moon. Not sure how true that is though.

Not even a little bit true.

All gasoline grades from reputable companies have plenty of additives in them for your engine. They will all do a fine job of keeping your injectors, valves and cylinders "clean".

Even Shell has made all grades Nitrogen enriched.

 

[uclabachelor]

worth it?

If it's worth the extra $0.40 / gal to make your car feel like it gained 10hp, then sure.

100 octane on a chipped 335i, on the other hand is :thumbsup:

 

[SandEagle]

i dont even know where the manual is. been putting 87 for a year. only a 25 cent diff between 87 and 93. 87 makes it run like crap. no wait, maybe its the 1.8L engine that does that.

 

[Viperoni]

My echo has a 10.5:1 CR and runs fine off of 87 octane... probably a little bit less DCR though haha

 

[exar333]

K20Z3
This inline-4 cylinder internal combustion engine is found in the US market Honda Civic Si (2006+) & Canadian market Acura CSX Type-S. It has an aluminum block with an aluminum head, and a bore and stroke of 86 mm x 86 mm, resulting in a 1,998 cc (121.9 cu in) displacement.

Displacement : 1,998 cc (121.9 cu in)
Compression : 11:1
Power: 197 bhp (147 kW) @ 7800 rpm (sae NET Rev 8/04)
Torque: 140 ft·lbf (189 N·m) @ 6200 rpm (sae NET Rev 8/04)
Redline: 8000 rpm
Fuel Cutoff: 8200 rpm
i-VTEC Engagement Window:5800 rpm

Yeah, that's gonna need premium

Wow. An econo-box engine that needs premium? Another fail point for the Si...

The Si specs look pretty good, if the car was from the 80's.

 

[LTC8K6]

Well, the new one has the 2.4L, which also needs premium.

 

[SparkyJJO]

What does the manual call for?

If it calls for lower, then anything higher is a total waste as it isn't designed for it. Can actually run worse on higher octane gas. My previous car would get 1-2mpg less when using 89 vs the 87 it was designed for.

 

[Ronstang]

K20Z3
This inline-4 cylinder internal combustion engine is found in the US market Honda Civic Si (2006+) & Canadian market Acura CSX Type-S. It has an aluminum block with an aluminum head, and a bore and stroke of 86 mm x 86 mm, resulting in a 1,998 cc (121.9 cu in) displacement.

Displacement : 1,998 cc (121.9 cu in)
Compression : 11:1
Power: 197 bhp (147 kW) @ 7800 rpm (sae NET Rev 8/04)
Torque: 140 ft·lbf (189 N·m) @ 6200 rpm (sae NET Rev 8/04)
Redline: 8000 rpm
Fuel Cutoff: 8200 rpm
i-VTEC Engagement Window:5800 rpm

Yeah, that's gonna need premium

Why does it need premium? Just because the compression ratio is 11:1? With aluminum heads and block it is more likely than not that it will run perfectly fine on 87. Aluminum carries heat away from the combustion chamber so fast that old rules on compression ratios and octane requirements are not valid. You actually have to raise the compression on all aluminum engines just to get back the power loss from not using cast iron.

If you run a higher octane that required you can actually LOOSE power and mileage since the fuel is harder to burn and thus you may not get complete combustion. I have verified this on a dyno more than once to non believers.

 

[LTC8K6]

The Si lists premium as the required fuel. Regular Civics do not.