3000 Rpm = 30 Mpg

[FTalento]

The Particulars.
My ride is an 06 SI with 20,100 miles. I always use Mobil 1 and surburban driving on Long Island so a mix of short bursts on the highway and reular 2 to 4 lane traffic with lights.

I have changed my driving on the parkways to 65mph at say 2800 rpm's. My last 2 tanks have yielded me 30 mpg.

In the past driving at between 70 and 75 mph and closer to 3500 rpm's lucky to get 25 mpg.

Moral of the story: I slowed down a bit and am getting much more range from a tankful. At $4.09 a gallon for 93 octane I feel a bit better. Just thought I'd share with you all.

[illusionstwice]

Nice write up. I started doing this about 3 weeks ago and have noticed a hell of an increase. I havent hit vtec since april 30th. I am trying to hold off my need for vtec until May 18th...the day of the big meet. So I can all day

[Gonzo]

How are you calculating that? You should be doing better.

My car nets around 31-32 at 70+.

If I actually did slow down to 65 I could probably get close to 35.

For reference the most efficient speeds are 65 in 6th and 45 in 5th according to some folks with scan guages.

[illusionstwice]

Originally Posted by Gonzo

How are you calculating that? You should be doing better.

My car nets around 31-32 at 70+.

If I actually did slow down to 65 I could probably get close to 35.

For reference the most efficient speeds are 65 in 6th and 45 in 5th according to some folks with scan guages.

Long Island Higways require one to merge with speed. People dont just let you in. So he might be using a lot of Vtec getting into highways.

[FTalento]

My fill up last night took 6.48 gallons and I covered 214 miles. I divided 214 by say 7 gallons as a rough number to get 30 mpg. Actually it comes to 32.97 mpg. But anything 30 mpg or over is great with these gas prices.

[-j-]

I did about 34 MPG going 68-70, but the buggers were on my tail even while in the slow lane. I've been setting cruise control around 72-73 and getting 29.

[OrdnanceMarine]

Originally Posted by Gonzo

How are you calculating that? You should be doing better.

My car nets around 31-32 at 70+.

If I actually did slow down to 65 I could probably get close to 35.

For reference the most efficient speeds are 65 in 6th and 45 in 5th according to some folks with scan guages.

For reference I've got a FA5 with just over 4000 miles on it. On cruise at 70 for 100+ miles on a flat highway (HWY 99 from Bakersfield to Fresno for those that have done this drive) I see ~35 MPG. I don't get 100 mile flat stretches like that to test it at 65 or below but I'd estimate that 65 will yield 36.5 MPG under the same conditions.

Originally Posted by Gonzo

For reference the most efficient speeds are 65 in 6th and 45 in 5th according to some folks with scan guages.

I've run a ScanGauge for years and the ScanGaugeII since I got my FA5 and in almost all situations with a competent driver you will get better mileage in 6th at 45 MPH as opposed to 5th. Basically the sooner you can shift the better for MPG. Exceptions would of course be if the lower gear can't provide you with the power needed causing the driver to ask too much of the engine in that gear sending the ECU into open loop, etc.

[david3558]

What RPM's do you guys usually cruise at? I mean around the 40-50 mph range.

[tsltd]

i have no idea how you guys get these numbers! i get from a range of 22-25 freeway and city combined...

[7002iSciviC]

i get roughly 24-25 all city driving with few hits

[I Vtec, do you?]

Originally Posted by Gonzo

How are you calculating that? You should be doing better.

My car nets around 31-32 at 70+.

If I actually did slow down to 65 I could probably get close to 35.

For reference the most efficient speeds are 65 in 6th and 45 in 5th according to some folks with scan guages.

You can't base other's mileage off of what you get yourself. My car gets 26-27 if I'm doing 70+, but I once hit 36 mpg (no joke) when I was doing CC at 55 for about 2/3 of the tank before I filled up.

I used to do 65 on the highway all the time and got around 27ish per tank, lately I've been doing 60 and I'm getting 29-30 on each tank now.

[rcracin13]

Originally Posted by illusionstwice

Nice write up. I started doing this about 3 weeks ago and have noticed a hell of an increase. I havent hit vtec since april 30th. I am trying to hold off my need for vtec until May 18th...the day of the big meet. So I can all day

you sir are crazy. that's 7 days without vtakkkk. i couldnt do it unless i didnt drive the Si for 7 days. i just vtakked 5 minutes ago

[06NaviEX]

I'm still on my factory oil fill, but I do have Amsoil MTF. I ran a trip at 75 to 80 mph, and got just over 30 mpg.

My car only has about 2,200 miles on it. As it breaks in more, the mileage always goes up. There is no doubt in my mind that I could get better than 32 mpg on a long road trip.

[Civic06SiR]

I'm lucky if I get 30 mpg. With all the bolt on mods you can have, doesn't that effect your mpg?

[OrdnanceMarine]

Originally Posted by david3558

What RPM's do you guys usually cruise at? I mean around the 40-50 mph range.

I used my GPS set in KM/HR mode and switched my Si to read KM/HR and found out that my car reads about 1.5KM/HR slow at 103 KM/HR (more accurate since KM is a smaller unit than MI. Then using my ScanGaugeII I adjusted my speed to read 3000 RPM and that's right at 69 MPH true speed. That's roughly 43.5 RPM/MPH so 40 MPH in 6th = 1740 RPM and 50 MPH in 6th = 2175 RPM. If you asked this question about my auto tranny CR-V I'd say "I dunno" since the slush box won't lock up and provide a fixed ratio until you're going nearly highway speeds.

[OrdnanceMarine]

Originally Posted by Civic06SiR

I'm lucky if I get 30 mpg. With all the bolt on mods you can have, doesn't that effect your mpg?

Starting from the front end and working back I've done the throttle body coolant bypass, then the P2R throttle body spacer and gaskets, intake manifold gasket (with the bypass and IMG the TBS gaskets are irrelevant but needed for proper spacing), Vibrant header with HFC, Vibrant exhaust. Some of these mods I thought it would slightly hurt MPG but I get amazing mileage out of my Si.

I'm still on factory fill oil at just over 4000 miles but will be changing to Penzoil Platinum any day now in preparation for getting the Hondata reflash and doing some dyno runs since I'd rather get the factory fill out if I'm going to be doing a half dozen runs on a dyno now that the engine has had time to do it's break in.

[bsbabcock]

As I'm just over 1000 miles now on the new Si, I've "discovered" vtec.. Interesting.. It kicked upwards into 6k rpm range, then I heard something then all the sudden the engine started "breathing" better. So I'll have to learn up about how Vtec works.

However, if the goal is mpg's, I'd NEVER get up into that kind of RPM range I'd think, rendering vtec completely useless really.. plus, the high vtec kick-in doesn't seem very beneficial for a daily commuter as I'd really rather not redline the thing all the time..

1st impressions from a brand spankin' new Si owner, coming from a Subie turbo with a bunch of low-RPM grunt, even prior to the turbo.

[habitat]

Originally Posted by tsltd

i have no idea how you guys get these numbers! i get from a range of 22-25 freeway and city combined...

I'm with you... I drive 50/50 and get those same numbers. Only on pure highway will I see numbers near 30mpg (usually a trip to SF from SJ and back).

[Teebo07si]

ive been getting about 31-35 mpg, mainly highway driving about 66 miles a day for work with 20,100 on it

[OrdnanceMarine]

Originally Posted by bsbabcock

As I'm just over 1000 miles now on the new Si, I've "discovered" vtec.. Interesting.. It kicked upwards into 6k rpm range, then I heard something then all the sudden the engine started "breathing" better. So I'll have to learn up about how Vtec works.

However, if the goal is mpg's, I'd NEVER get up into that kind of RPM range I'd think, rendering vtec completely useless really.. plus, the high vtec kick-in doesn't seem very beneficial for a daily commuter as I'd really rather not redline the thing all the time..

1st impressions from a brand spankin' new Si owner, coming from a Subie turbo with a bunch of low-RPM grunt, even prior to the turbo.

Get rid of the silly "VTEC Kick" with Hondata's ECU reflash. This + at least a header will dramatically improve the mid range on the K20Z3.