Guys with 3.91 gears in a 6spd manual - Page 3 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Mikamaro · 01-29-2015, 04:49 PM

Quote:

Originally Posted by Burt

I think you're going to need to do some more engine work to sustain those kinds of rpm....

If you want to be able to satisfy all your own questions, us this formula:

Tire Revolutions Per Mile: For a stock tire, use 726, but if you're running something different, Tire Rack will list it under the tire specs.

Multiplied by...

Speed, in MPH. This converts revs per mile into revs per hour at the speed you're interested it.

Divided by...

60 minutes per hour. Dividing by 60 converts tire revs per hour to revs per minute.

Multiplied by...

Final Drive Ratio. Since we're looking at the 3.91s, use 3.91, but this works for any other ratio set.

Multiply one more time by...

Specific gear ratio. The standard SS (MM10) uses the following ratios: 1st-3.01, 2nd-2.07, 3rd-1.43, 4th-1.00, 5th-0.84, 6th-0.57. Use the one you're interested in, and voila! You've figured out your engine RPM. You can shuffle the equation to figure out vehicle speed, which would make it RPM x 60 / (tire revs per mile x final drive ratio x gear ratio)

All right! Thanks, That's helpful. let me crunch those numbers...

LS3 Handler · 04-26-2015, 02:42 AM

I know this thread is a little dated but i had a question for daily driving with the 3.91s. I know most will say that they didn't get a camaro for the MPG and neither did i but less i spend on gas the more i can spend on mods. Under normal driving conditions did ya'll noticed much drop in MPG. Also how about highway driving 60-80 mph and MPG there respectively.

homewrecker · 04-26-2015, 03:18 AM

Every week I drive 120 miles one way home after my shift, so about 240 round trip, and about 50 misc miles, so around 300 a week. The majority of the time I can get a way with a full tank per week and I don't baby it either. Although I have nothing scientific, according to the DIC, I average 17 in the city and on my long drives home it always bumps back up to 17.5. (In 6th gear). I haven't cleared the mpg ever and I know I can get better gas mileage but it's all worth it because I love my 3.91!

Sent from my iPhone using Tapatalk

Killermoose · 04-26-2015, 10:07 AM

I've had mine done for about 4 months. I do a lot of around town driving and a little hwy. Overall it's not that much different than what it was before. The last time I was on the hwy for about 140 mile trip it was around 24 mpg still.

sherob · 04-26-2015, 12:33 PM

Mine is a DD... 80 miles a day round trip... w/ stop and go traffic and 75mph speed limit on a long stretch ( suggested speed

) , I avg 17.7mpg right now... and I'm a pretty aggressive driver... mileage isn't my priority.

Dave@Sturgiscamarorally · 04-26-2015, 10:27 PM

Since having mine installed I noticed a small MPG difference @ 65 to 75 MPH, maybe 1 MPG. above 80 it drops about 2.5-3 MPG depending on wind LOL. In town I lost about 3 MPG. But i tend to have a heavy foot. Most time RPMs are north of 2K

bleavens1962 · 04-27-2015, 09:13 AM

Had mine done a month ago...Daily driver averaging around 20mpg,3000rpm translates to 85 (6th gear)..Definitely a worthwhile mod..2014 1LS (6 speed), CAI cold air, Vmax TB, HP Tune (thanks Matt @ FSP), Flowmaster Thunder 40series axleback exhaust, Elite Catch Can.

TECHTURTLE · 04-30-2015, 10:51 AM

19.1 MPG average with mostly highway miles.

04-26-2015, 10:07 AM	#32
Killermoose Drives: 2014 SS Join Date: Jul 2014 Location: Duluth, Ga Posts: 51 View My Garage	I've had mine done for about 4 months. I do a lot of around town driving and a little hwy. Overall it's not that much different than what it was before. The last time I was on the hwy for about 140 mile trip it was around 24 mpg still. __________________ BMR lowering springs, GM strut tower brace, Z28 Air Intake, 3.91 gear, LG long tube headers no cats, Elite catch can, Remote clutch resevoir, Hurst short throw shifter

04-26-2015, 10:27 PM	#34
Dave@Sturgiscamarorally Drives: 2010 ABM 1SS Join Date: Nov 2014 Location: South Dakota Posts: 199	Since having mine installed I noticed a small MPG difference @ 65 to 75 MPH, maybe 1 MPG. above 80 it drops about 2.5-3 MPG depending on wind LOL. In town I lost about 3 MPG. But i tend to have a heavy foot. Most time RPMs are north of 2K __________________ 2010 Aqua Blue 1SS KWC 3pc forged, Seibon hood, ZL front end, MGW, ARH full exhaust w/ Doug Thorley axle back, BTR4, Roto-fab, LSXR 102, NW 102, 3.91s

04-27-2015, 09:13 AM	#35
bleavens1962 Drives: 2014 1LS Camaro Join Date: Jun 2014 Location: Tampa Fl Posts: 517 View My Garage	Had mine done a month ago...Daily driver averaging around 20mpg,3000rpm translates to 85 (6th gear)..Definitely a worthwhile mod..2014 1LS (6 speed), CAI cold air, Vmax TB, HP Tune (thanks Matt @ FSP), Flowmaster Thunder 40series axleback exhaust, Elite Catch Can. Last edited by bleavens1962; 04-30-2015 at 02:51 PM.

04-30-2015, 10:51 AM	#36
TECHTURTLE Drives: 2016 Camaro 2SS Join Date: Dec 2013 Location: OTP Atlanta Posts: 862 View My Garage	19.1 MPG average with mostly highway miles. __________________ 2016 2SS 6-Speed Manual... Magnetic Ride Control, Dual Mode Exhaust, Sunroof, Adrenaline Red Interior, Mylink W/Navigation Added Edelbrock E-Force Supercharger, GM 1LE Sway Bars, BMR Upper/Lower Trailing Arms, BMR Upper Control Arms. BMR Front/Rear Chassis Braces, BMR Tunnel Brace. GM Red knee Pads, GM Black Front Splitter, GM SEMA Concept Grille, GM Dark Taillights, GM Ground Effects package... Savini Di Forza BM-14 Gloss Black Wheels 9's front, 10's rear.

04-26-2015, 02:42 AM	#30
LS3 Handler I love the LS3 Drives: 2010 IOM 2SS Manual Join Date: Dec 2012 Location: Washington NC Posts: 361	I know this thread is a little dated but i had a question for daily driving with the 3.91s. I know most will say that they didn't get a camaro for the MPG and neither did i but less i spend on gas the more i can spend on mods. Under normal driving conditions did ya'll noticed much drop in MPG. Also how about highway driving 60-80 mph and MPG there respectively.

04-26-2015, 03:18 AM	#31
homewrecker Drives: '04 Z06, '14BMW M235i, '15 SS/1LE Join Date: Feb 2014 Location: San Diego/Los Angeles Posts: 845	Every week I drive 120 miles one way home after my shift, so about 240 round trip, and about 50 misc miles, so around 300 a week. The majority of the time I can get a way with a full tank per week and I don't baby it either. Although I have nothing scientific, according to the DIC, I average 17 in the city and on my long drives home it always bumps back up to 17.5. (In 6th gear). I haven't cleared the mpg ever and I know I can get better gas mileage but it's all worth it because I love my 3.91! Sent from my iPhone using Tapatalk

04-26-2015, 12:33 PM	#33
sherob Drives: 2015 SW 1SS/RS 1LE Join Date: Mar 2015 Location: Brighton, CO Posts: 2,736	Mine is a DD... 80 miles a day round trip... w/ stop and go traffic and 75mph speed limit on a long stretch ( suggested speed ) , I avg 17.7mpg right now... and I'm a pretty aggressive driver... mileage isn't my priority.