Go Back   EcoModder Forum > EcoModding > General Efficiency Discussion
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 02-24-2009, 11:08 PM   #1 (permalink)
Master EcoModder
 
Join Date: Mar 2008
Location: southern, wv
Posts: 353

Johnny 5 - '81 Honda Cm400e
90 day: 42.86 mpg (US)

Da bike - '06 Honda Shadow Vlx deluxe
90 day: 59.47 mpg (US)
Thanks: 18
Thanked 8 Times in 5 Posts
2000 rpm

my friend and i were talking about gear ratios, and some how he said about 2k rpm was the best rpm for mpg. my question was yeah on what size motor.
then he correted and said smaller motors nee high rpm to cruise at tha same hp. well to do 55 mph my 98 taco needs about 40hp.

that got me to thinking what mph are you guys at, at 2000rpm in top gear?

98 4x4 tacoma 2.7 5 speed manual. 59mph@2k rpm
09 4x4 tacoma 4.0 5 speed auto 67mph at 2k rpm
07 camry se 2.4 5 speed auto 63mph at 2k rpm.

if i remember correctly
09 silverado 4x4 5.3 4 speed auto 80 mph at 2k rpm.

__________________
.
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 02-24-2009, 11:58 PM   #2 (permalink)
Master EcoModder
 
Ryland's Avatar
 
Join Date: Jan 2008
Location: Western Wisconsin
Posts: 3,903

honda cb125 - '74 Honda CB 125 S1
90 day: 79.71 mpg (US)

green wedge - '81 Commuter Vehicles Inc. Commuti-Car

Blue VX - '93 Honda Civic VX
Thanks: 867
Thanked 433 Times in 353 Posts
my civic 1.5 vx 2k rpm I think is right around 60 mph, my old crx hf 2k rpm was around 68mph with the 1.5 engine that put out a peek of 58hp... it's really what it is tuned for, just replacing my civic exhaust made a difference, the old exhaust was larger around and that low end power came back as soon as I went with the stock small exhaust, mileage started to come back up as well even with the cold.
  Reply With Quote
Old 02-25-2009, 12:11 AM   #3 (permalink)
Master EcoModder
 
NeilBlanchard's Avatar
 
Join Date: May 2008
Location: Maynard, MA Eaarth
Posts: 7,901

Mica Blue - '05 Scion xA RS 2.0
Team Toyota
90 day: 42.48 mpg (US)

Forest - '15 Nissan Leaf S
Team Nissan
90 day: 156.46 mpg (US)

Number 7 - '15 VW e-Golf SEL
TEAM VW AUDI Group
90 day: 155.81 mpg (US)
Thanks: 3,466
Thanked 2,937 Times in 1,837 Posts
Hi,

IIRC, my xA is only going about 40mph in 5th gear at 2K RPM. To go 60mph, is ~3200 RPM... I need taller gears, and/or a final drive under 4:1.
__________________
Sincerely, Neil

http://neilblanchard.blogspot.com/

Last edited by NeilBlanchard; 02-25-2009 at 10:07 AM..
  Reply With Quote
Old 02-25-2009, 07:25 AM   #4 (permalink)
Custom User Title
 
Join Date: Jul 2008
Location: Bozeman, MT
Posts: 248

Daily Driver - '02 Pontiac Grand Prix SE
90 day: 18.45 mpg (US)
Thanks: 1
Thanked 6 Times in 5 Posts
I think my truck is at 58mph or close to. The car I think is 65mph or close to. I know the car runs under 2K at 60mph, and the truck is real close, might even be dead on. Very different motors, very different gearing. The truck runs out much faster.
__________________
  Reply With Quote
Old 02-25-2009, 07:37 AM   #5 (permalink)
EcoModding Apprentice
 
Join Date: Jan 2009
Location: Macon,GA
Posts: 176

Ruint Taco - '19 Toyota Tacoma SR Double Cab
90 day: 23.76 mpg (US)
Thanks: 124
Thanked 43 Times in 34 Posts
2000 rrpm is just a rule of thumb. The rpm for best economy could vary a lot depending on engine design.

My car gets it's best at ~1600 rpm,
  Reply With Quote
Old 02-25-2009, 09:05 AM   #6 (permalink)
Master EcoModder
 
Ryland's Avatar
 
Join Date: Jan 2008
Location: Western Wisconsin
Posts: 3,903

honda cb125 - '74 Honda CB 125 S1
90 day: 79.71 mpg (US)

green wedge - '81 Commuter Vehicles Inc. Commuti-Car

Blue VX - '93 Honda Civic VX
Thanks: 867
Thanked 433 Times in 353 Posts
I've heard that best mileage is close to the peek torque, not sure if this true or not but if you look at the big chilton repair books they give torque for different engines and the range for civics is between 2,000 rpm for the crx hf's an up to 5000 rpm for some of the SI engines, so it so it does vary alot, you can't make blanket statments.
  Reply With Quote
Old 02-25-2009, 09:13 AM   #7 (permalink)
Master EcoModder
 
Join Date: Aug 2008
Location: South Dakota
Posts: 460

WonderWagon - '94 Ford Escort LX
Last 3: 51.52 mpg (US)

DaBluOne - '99 Ford Escort SE
90 day: 48.97 mpg (US)

DaRedOne - '99 Ford Escort ZX2 Hot
Thanks: 0
Thanked 15 Times in 4 Posts
Quote:
Originally Posted by Vwbeamer View Post
2000 rrpm is just a rule of thumb. The rpm for best economy could vary a lot depending on engine design.

My car gets it's best at ~1600 rpm,
Not just engine design. Toss the same engine in a heavier car (or add three over weight adult passengers - say 250lbs each - to the current car) and the most efficient rpm will be significantly greater than 1600 rpm.
  Reply With Quote
Old 02-25-2009, 09:30 AM   #8 (permalink)
EcoModding Apprentice
 
Join Date: Feb 2009
Location: UK
Posts: 162
Thanks: 2
Thanked 2 Times in 2 Posts
If i remember correctly:
1.1L Fiat Punto (1996 model), 5th gear at 2000rpm = about 40mph.
30 mph is about 1600rpm..
  Reply With Quote
Old 02-25-2009, 11:46 AM   #9 (permalink)
Master EcoModder
 
Join Date: Feb 2009
Location: Phoenix
Posts: 595
Thanks: 106
Thanked 113 Times in 71 Posts
I don't claim to be a master of internal combustion engine wisdom, but coming from an expedition vehicle background the rule of thumb has always been to gear (axles) and/or shift (manual trans) so your most frequent travel speed coincides with the torque peak RPM of your engine. Fuel efficiency for expedition vehicles is important, not as much for financial reasons but because of the distance that may exist between fuel stations.
  Reply With Quote
Old 02-25-2009, 12:06 PM   #10 (permalink)
Master EcoModder
 
Join Date: Jun 2008
Location: London, Ontario
Posts: 1,096

2k2Prot5 - '02 Mazda Protege5
90 day: 33.82 mpg (US)
Thanks: 0
Thanked 17 Times in 14 Posts
i'm also doing about 40 at 2krpm in fifth... it is disgusting. I'd rather be at 60. That's a big difference.

  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Can low rpm damage the engine? KiaRio2004 Hypermiling / EcoDriver's Ed 24 10-03-2017 04:16 PM
Honda IACV explained TomO Off-Topic Tech 16 12-21-2015 02:49 AM
What is the ideal RPM to cruise at? Krunko Hypermiling / EcoDriver's Ed 15 05-16-2009 05:11 PM
VX owner needs help. RPM is incorrect. XyKo Off-Topic Tech 5 08-23-2008 03:27 PM
MetroMPG.com mailbag: is lowest RPM really best for max MPG with big displacement? MetroMPG Hypermiling / EcoDriver's Ed 20 01-06-2008 02:00 PM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2022, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com