Civic Si: Your Gas Mileage

[EzK]

32 from Baltimore MD to Greensboro NC.

That was exciting. 30 on the way back though.

[darita]

First tank using the SGII. 95 percnet of the trips I took averged in the 30's. I fully expected to break 30 on my next fillup. Well, I didn't. Infact, I was 1 MPG lower! What's up?

[KJSatz]

You need to calibrate it to your fillups to get it really spot on.

[whyycharles]

driving in ny is pretty bad average 23-24 ...

[6SpeedTA95]

Recent tanks have varied from 27 to 29 with it being cold.

I would expect that number to start creeping up as we get into march.

[mongoose221]

my car is new, has less than 800 miles, should i expect MPG to increase as it's broken in? 05 mazda6 which i traded in actually got worse after it crossed 25k miles

[OrdnanceMarine]

Originally Posted by mongoose221

my car is new, has less than 800 miles, should i expect MPG to increase as it's broken in? 05 mazda6 which i traded in actually got worse after it crossed 25k miles

Yes, it will get better with time both because it breaks in and because you learn to drive it for maximum efficiency (when you want to and if you try to).

If you're looking for some break-in tips be sure to minimize the amount of time your car idles when cold. Drive it gently until completely warmed up (at least 5 miles in mild weather and more like 10 miles in cold weather) and then start working the engine to higher and higher RPMS with increasing amounts of throttle being sure to leave it in gear and ride the engine compression back down and then repeat. Consider changing the oil for the first time ~3000 miles if you're in a cold climate and driving a lot in the city or if you absolutely have to idle your engine a lot before it's warmed up, and maybe 4000 miles otherwise. Go with a good mineral motor oil or one of the less expensive synthetic 5W30's like Pennzoil Platinum and a good inexpensive filter like the Purolator PureOne. Using this method for my recent Hondas I have two K-Series engines that burn less than 1/2 qt per oil change (~11k miles in my CR-V and ~8000 miles in my Si and I'm pushing them longer and longer), turn in excellent used oil analyses, and especially in the case of my Si, generate exceptional MPG and power.

[FMZ]

My question to everybody in this thread is that if you guys/gals are still seeing the same MPG with different set of tires other then OEM MXM4s? I have close to 45000 miles on my stock tires and they're getting scary now. I am in the market for new tires, but due to conflicting data, I am not sure which tires to get. I travel about 62 miles a day and usually get between 31-32MPG with tires PSI set at 32-33PSI.
Any info on what tires people are running would be appreciated.

[OrdnanceMarine]

Originally Posted by FMZ

My question to everybody in this thread is that if you guys/gals are still seeing the same MPG with different set of tires other then OEM MXM4s? I have close to 45000 miles on my stock tires and they're getting scary now. I am in the market for new tires, but due to conflicting data, I am not sure which tires to get. I travel about 62 miles a day and usually get between 31-32MPG with tires PSI set at 32-33PSI.
Any info on what tires people are running would be appreciated.

I switched a few weeks ago to a set of Maximum Performance Summer Sumitomo HTR ZIII's on lightweight rims and the rolling resistance is definitely higher (I've had to adjust my hypermiling coasting practices by waiting until I'm closer to the stop or starting my coast at a higher speed). I took a 400 mile trip this weekend where I probably would have seen ~38 MPG before and instead saw 34-35 MPG (I don't have my SG2 running since I've been datalogging with FlashPro so I only have data at each fill). I don't know if all of the difference is the tires because I also switched to FlashPro and a custom MAP tune shortly before than and may have bbq'ed my primary O2 which may be negatively affecting my MPG.

[PolishArt]

When I go on long trips from LA to Vegas I see 32MPG.....To and from work and were ever else I decide to go in LA between 23-25MPG.....I have seen as bad as 20MPG but I was Vtec happy like a mofo!

[CivicEX]

I just got 28 on mine and I'm pushing for 30 on the next fill up. I really don't NEED Vtec the ways I go. Shift before 3 and when I need to move 4-5 is enough to get me going enough to pass.

so if anyone knows how to start a chart r graph for this please feel free to do so.

Lets see what we can actually get. I know one of us can get at-lest 32mpg with the si. I have already started.

Thanks for reading

- CivicEX

[francis_nighthawk]

I only get 17..

[bouncer07]

My automatic 2009 Corolla LE only gets 28-29 mpg!! What the FOCK!!

[des_si]

the best mpg i've gotten in my 08 Si was 33 on the freeway :O In the city, as long as i'm taking her easy, I can get as much as 29

[CivicEX]

Originally Posted by des_si

the best mpg i've gotten in my 08 Si was 33 on the freeway :O In the city, as long as i'm taking her easy, I can get as much as 29

WOW, to me, that is impressive. I can't beat 28.

[des_si]

yeah, I did a lot of research when I first got the car and found that when it is properly broken in it can really affect the gas mileage. I was very careful with the car for the first 10,000 miles and I think that's what helped it

[Hawn Si]

Originally Posted by bouncer07

My automatic 2009 Corolla LE only gets 28-29 mpg!! What the FOCK!!

Might be the gas pedal telling you to try and go a little faster, ...or it'll just do it for you.

[OrdnanceMarine]

Originally Posted by des_si

yeah, I did a lot of research when I first got the car and found that when it is properly broken in it can really affect the gas mileage. I was very careful with the car for the first 10,000 miles and I think that's what helped it

What's your definition of "very careful"? I was very careful to fully warm up the engine and run it through all possible speeds and increasing loads well before 1000 miles making sure to let the car ride the engine down under high vacuum as well. I have put down great numbers on the dyno and get incredible mileage (less so now that I'm running maximum performance summer tires). Hopefully you don't think it's necessary to be very gentle on this car through 10,000 miles to achieve good MPG (just checking).

[OrdnanceMarine]

Originally Posted by bouncer07

My automatic 2009 Corolla LE only gets 28-29 mpg!! What the FOCK!!

Just goes to show that the Si's engine is exceptionally versatile. Small displacement and MT really help keep it efficient at low loads. The amazing ability to breathe through speeds that most similar engines would explode at mean you can get great power when you want.

[des_si]

Originally Posted by OrdnanceMarine

What's your definition of "very careful"? I was very careful to fully warm up the engine and run it through all possible speeds and increasing loads well before 1000 miles making sure to let the car ride the engine down under high vacuum as well. I have put down great numbers on the dyno and get incredible mileage (less so now that I'm running maximum performance summer tires). Hopefully you don't think it's necessary to be very gentle on this car through 10,000 miles to achieve good MPG (just checking).

By very careful, i meant that I made sure to evenly run through all gears the first couple hundred miles (not only city driving or hwy driving), and never vtec before it's fully warmed up.

Oh, also, no tracking or autox prior to 10,000 miles. That probably doesn't matter as much, but I did it just to be certain!