Okay so my test is as done as it's gunna be, i have stayed under 4000 rpms in first gear and around 3k in other gears. I have used 1/2 of a tank and got 120 miles. I am giving up on the test cause it's so boring driving like that, so basically i would get an additional 35 miles if i were to use the whole tank. Which personally isn't worth it to me because it was pretty boring. PS: I'm still on the L flash.

 

I tried to do a tank without going over 3500 but I could not do it!

I did just put in 87 octane and the engine is noticeably rougher, louder, and more sluggish, although it still purrs like a kitten compared to anything else.

 

Weird.

I have 2 service technicians explicitly tell me to run 87 Octane because it burns a hotter flame front, produces more power per volume, and prevents carbon buildups. They also encouraged me to run the car "like it was meant to be" and not granny it around.

I get 14.5-17mpg with city driving, 21 highway.

I run 87 Shell almost exclusively. Engine purs...no rough idle, no knocking, no nothing other than sweet rotary audio.

 

hey guys don't get me wrong i still rev her, i'm @ 1400 miles now and can't wait to really get on it but I'm pretty much in a groove now. It still gets about ~22 mpg with my driving style about 300 miles to 14 gallons on a fill. lowest i've got is about 250 with mucho city driving whehn i got stuck in traffic for 5 hours after someone nearly bunt down our walmart

 

ok broke 3000 miles. Over the last 6 tanks here's the breakdown. 3 were 93 octane citgo 3 were 87 octane citgo. ( citgo gas happens to be the gas that my civic LOVES. I'm talking a whole diffrent car when I drive with citgo... when you pull and average 48 mpg ( over 3 years and 150k miles ) anything affect the driveability... and citgo gas has something to it I don't know what but it does )

ALL of the 87 octane tanks went over 300 miles ( one tank went 340 miles ) per fill @ 13.8 gallons. average 22 mpg. The car also feels much more perky, although there seems to be more "lope" at idle until it warms up.

gas was filled 87-93-87-93-87-93 from the same gas stations in the same week.

ALL of the 93 octane tank made average of 280 miles ( smallest was 238 miles ). about 20 mpg/ it runs smooth but it just didn't feel as good or as peppy. Also I get MUCH more carbon out the tailpipes. tail pipe cleaning is getting the be a hassle.


Almost all the driving was interstate, with some significant downshifting and passing @ high speed as well. about 15% city and 85% highway. I bascially drove my car to work for the last 2-3 weeks. I have a 52 mile one way commute that I usually use my honda civic hx ( avg 48 mpg ) for. I can rack up the milage pretty quickly.

That's about as real world as I can do guys. let me know what you think.

 

Thanks. That was the most scientific approach that I've seen yet. Good info!

 

Picking up my 8 on Saturday.

Is everyone calculating their MPG manually or does the 8 display the fuel consumption estimations like some other cars?

 

i get better mileage with 87 also but i also noticed that when i put the car in first gear and accelerate it hesitates more so back to 93.

 

if you have a odb2 scanner and a computer it's cake to calculate your mileage on the fly. there's nothing stock. even then the cpu is guessing by a/f ratio and consumption and driveshaft rotation, which can vary. I like the plain old tried and true logbook/gas recipt method. after 5-6 tanks the margin of error becomes low enough you know what gas milage you usually get.

 

Mine just turned 9k in miles. Milage has always been 17-19, but seems to have increased in the last 1000miles. This week had more highway driving than usual and hit 292 miles on 13.6 gal. I've run all different grades and saw no difference. Now run 87 full time because the owner's manual says I can...higher octane is only recommended, not required.

 

agreed

 

If you're in an area with higher temperatures during the day, wouldn't it be easier for the fuel to predetonate using lower octane gas? I can see maybe chancing 87 during the winter, but during the summer? The car gets so hot on its own already...

 

maybe if it was dry but when it's hot here the humidity is always near or at 100%. this actually could play a big part of this. wonder if the maf sensor or something is overly sensitive to humidity?

to those of you who keep saying that 93 or whatever is their "piece of mind" this car has a VERY sensitive knock sensor. if that were kicking in it'd severely hurt gas mileage and performance from retarding the spark in the engine. so far i feel my cars runs better on cheaper 87 fuel. it's most certainly perkier and more peppy while getting better fuel economy.

what this tells me is that this engine is fine on this particular 87 octane fuel.

keep in mind that pump rating are ron ( the higher number, 87 might have a ron of 92 this is the stress free load like idle ) and mon ( the lower number, 87 might have a mon of 82 this is under stress or heavy load ) the two numbers averages together are the pump rating for the minimum.

gasoline blends vary wildly, and some have much higher mons. these are "good" gasolines ( name brands ). "shitty" gas ( the knock off and no name places ) tends to have a very low mon and a higher ron. you get this gas under a load and it pings like hell.