Go Back   EcoModder Forum > EcoModding > Hypermiling / EcoDriver's Ed
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 10-06-2014, 04:23 AM   #1 (permalink)
EcoModding Lurker
 
Join Date: Oct 2014
Location: England
Posts: 8
Thanks: 0
Thanked 1 Time in 1 Post
What is the optimum speed for highway / Motorway travel?

Hello all,

First time poster long time website reader!

I travel to work on a long highway for about 20 miles and I do 56 mph. As I have read and been told this is the optimum speed for fuel economy. A lot of the lorries (trucks!) go at this speed and they need to drive for fuel economy!

Or is 56 mph not the golden number? Is it 65 mph? I have heard people say that.

I am getting 64 mpg from my Ford Fiesta 1.6 TDCi I am very pleased but of course I would like a higher MPG! I have started turning the engine off and coasting down hills. I live in a very hilly part of england which is great! I have also started block gear changing from third to fifth and also doing 30 mph in top gear. I am sure those two techniques will improve my personal best go 64 mpg!

I mainly do motorway driving for my commute to and from work.

I am also getting about 450 miles out of 3/4's of a tank. I never fill the tank as this adds weight! I am considering only filling half a tank but 3/4 lasts me a week and I hate going to the fuel (gas) station!

I am looking into modding my diesel with a remap and some new low rolling resistance continental Eco Contact 5 tyres. This I am sure will get me over the 70 mpg which is hybrid territory!

I also want to get some moon caps! but I can't find any in the uk. Is it easy to make them?

Thanks for your help!

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 10-06-2014, 04:59 AM   #2 (permalink)
Not Doug
 
Xist's Avatar
 
Join Date: Jun 2012
Location: Show Low, AZ
Posts: 12,186

Chorizo - '00 Honda Civic HX, baby! :D
90 day: 35.35 mpg (US)

Mid-Life Crisis Fighter - '99 Honda Accord LX
90 day: 34.2 mpg (US)

Gramps - '04 Toyota Camry LE
90 day: 35.39 mpg (US)

Don't hit me bro - '05 Toyota Camry LE
90 day: 35.79 mpg (US)
Thanks: 7,217
Thanked 2,217 Times in 1,708 Posts
Sounds like a job for http://ecomodder.com/forum/showthrea...you-15182.html!

I have heard 55 MPH many times, although I have not read it in these forums, just that it is better than 60, let alone 65, or eighty. Generally speaking, the slower that you drive, the better, but about a liter of gas an hour just idling. The best way to know for sure is with instrumentation, which can be as simple as an OBD-II dongle and Torque or another app. You can get an idea of this in: http://ecomodder.com/forum/showthrea...0-a-30169.html
  Reply With Quote
The Following User Says Thank You to Xist For This Useful Post:
MetroMPG (10-06-2014)
Old 10-06-2014, 05:45 AM   #3 (permalink)
EcoModding Lurker
 
Join Date: Oct 2014
Location: England
Posts: 8
Thanks: 0
Thanked 1 Time in 1 Post
I do know that the US mpg is different to the mpg in the UK. So my 64 mpg will be different than the US mpg. A gallon of fuel in the uk is 4.5 litres I am not sure what the US conversion is!

I am very happy with my diesel it cost £42 to do 450 miles very good! could and will be better! lol
  Reply With Quote
Old 10-06-2014, 06:38 AM   #4 (permalink)
EcoModding Apprentice
 
adam728's Avatar
 
Join Date: May 2008
Location: Michigan
Posts: 161

Mazda3 - '08 Mazda 3 S
90 day: 29.65 mpg (US)

DR650SE - '13 Suzuki DR650SE
90 day: 46.16 mpg (US)

Wife's - '12 GMC Terrain SLE-2
Thanks: 2
Thanked 22 Times in 18 Posts
A US gallon is 3.79 liters, so US mpg is considerably lower than a UK mpg.

That said, the charts Xist linked to still will show the exact same trend, regardless of US mpg or UK mpg. Speaking very generally the best mileage is the slowest speed that top gear can be held.
__________________
  Reply With Quote
Old 10-06-2014, 07:57 AM   #5 (permalink)
Master EcoModder
 
oldtamiyaphile's Avatar
 
Join Date: May 2009
Location: Australia
Posts: 1,510

UFI - '12 Fiat 500 Twinair
Team Turbocharged!
90 day: 40.3 mpg (US)

Jeep - '05 Jeep Wrangler Renegade
90 day: 18.09 mpg (US)

R32 - '89 Nissan Skyline

STiG - '16 Renault Trafic 140dCi Energy
90 day: 30.12 mpg (US)

Prius - '05 Toyota Prius
Team Toyota
90 day: 50.25 mpg (US)

Premodded - '49 Ford Freighter
90 day: 13.48 mpg (US)

F-117 - '10 Proton Arena GLSi
Pickups
Mitsubishi
90 day: 37.82 mpg (US)

Ralica - '85 Toyota Celica ST
90 day: 25.23 mpg (US)

Sx4 - '07 Suzuki Sx4
90 day: 32.21 mpg (US)

F-117 (2) - '03 Citroen Xsara VTS
90 day: 30.06 mpg (US)
Thanks: 325
Thanked 452 Times in 319 Posts
Quote:
Originally Posted by mada88 View Post
I am getting 64 mpg from my Ford Fiesta 1.6 TDCi I am very pleased but of course I would like a higher MPG! I have started turning the engine off and coasting down hills. I live in a very hilly part of england which is great!
Be careful you don't kill your turbo by turning the engine off while it's hot. You don't need to turn off your engine on a steep hill anyway as if you leave it in gear the engine won't use any fuel anyway, and you'll save the brakes. If the hill isn't that steep, just put in in neutral. Your car probably uses only 0.6l/hr at idle.
__________________






  Reply With Quote
Old 10-07-2014, 07:37 AM   #6 (permalink)
Master EcoModder
 
Joggernot's Avatar
 
Join Date: Jun 2013
Location: Texas
Posts: 449
Thanks: 1,748
Thanked 126 Times in 105 Posts
Using ScanGage on the Honda Accord V6 I found that 50-55 mph got the best mileage. Previous Honda (1986) seemed to be better at 45 mph. So you got to look at the charts to see where to start your testing. YMMV.
  Reply With Quote
Old 10-07-2014, 11:23 AM   #7 (permalink)
Master EcoModder
 
Ecky's Avatar
 
Join Date: Dec 2011
Location: New Zealand
Posts: 5,005

ND Miata - '15 Mazda MX-5 Special Package
90 day: 42.54 mpg (US)
Thanks: 2,866
Thanked 2,501 Times in 1,547 Posts
The best speed for economy is generally the slowest you can go in top gear. Anything higher than that is compromising to there faster.



There's a thread on here somewhere about speed vs MPG. I think the only notable exception was in a Corolla, which actually delivered its best economy in 4th gear, rather than 5th (?)

  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com