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

Reply  Post New Thread
Submit Tools LinkBack Thread Tools
Old 01-10-2021, 04:32 PM   #1 (permalink)
Master EcoModder
Ecky's Avatar
Join Date: Dec 2011
Location: Michigan
Posts: 4,511

Gaptooth (retired) - '00 Honda Insight
Team Honda
Gen-1 Insights
90 day: 54.26 mpg (US)

Such Fit - '07 Honda Fit Sport
90 day: 41.27 mpg (US)

K-sight - '00 Honda K-sight
Team Honda
90 day: 33.82 mpg (US)

Aerocivic - '92 Honda Civic CX
90 day: 64.49 mpg (US)
Thanks: 2,346
Thanked 2,091 Times in 1,302 Posts
VW Íko-Polo - 138mpg?

I just came across this autoblog article:


VW claimed it made 138mpg during a test drive, using an be 850cc supercharged diesel.

I personally think that sounds a bit high, even for diesel. Maybe these were UK gallons?

Neat car though.

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

Old 01-10-2021, 08:00 PM   #2 (permalink)
It's all about Diesel
cRiPpLe_rOoStEr's Avatar
Join Date: Oct 2012
Location: Porto Alegre, Rio Grande do Sul, Brazil
Posts: 10,510
Thanks: 0
Thanked 1,277 Times in 1,131 Posts
Sure that sounds quite optimistic for such an old-school ride, but Diesels tended to respond greatly to forced induction anyway. It's also important to take note on any specific condition of that test-drive which might have influenced the results.
  Reply With Quote
Old 01-11-2021, 04:17 AM   #3 (permalink)
Master EcoModder
Stubby79's Avatar
Join Date: Sep 2012
Location: Victoria, BC
Posts: 1,746

Firefly EV - '98 Pontiac Firefly EV
90 day: 107.65 mpg (US)

Little Boy Blue - '05 Toyota Echo
90 day: 33.35 mpg (US)

BlueZ - '19 Nissan 370Z Sport
90 day: 17.19 mpg (US)
Thanks: 75
Thanked 570 Times in 425 Posts
Superchargers are known for increasing efficiency on gasoline engines...but I assumed that was when at partial throttle, shoving more air in to each cylinder, getting it in to the more efficient part of the fuel map...something diesels don't have to be nearly so concerned with.

The 90's+ Buick 3.8 S/C cars get better gas mileage than the naturally aspirated versions, for example.

With a diesel no suffering from as much pumping losses, I'd have thought a turbo - that only really kicks in when you need a lot of power - would be the most efficient way of doing it.

Maybe it comes down to gearing...with even more low-end torque, you could run that sucker at like 1300rpm and still make enough power to keep it moving.

Probably UK gallons.

From Wikipedia:

An extremely fuel-efficient two-cylinder diesel was prototyped in the mid-1980s with a G40 supercharger to overcome its small capacity, although this did not make production. A high-fuel-efficiency model which did make production was Formel E (E for Economy), introduced in 1983. This used a high-compression 1272 cc engine, longer gear ratios and an early-stop-start ignition system (called SSA) that would cut the engine when idle for more than two seconds to save fuel whilst temporarily stopped in traffic, and restart the engine when the gear lever was moved to the left in neutral. The system could be enabled or disabled by means of a toggle switch below the light switch. Similar systems were later used on the Volkswagen Golf Mk3. Similar systems were developed by other car manufacturers.
That about covers it...an undersized engine with a supercharger to make up for it, potentially having the tall gearing and everything else they put in the non S/C versions later on. In a car that weighed about the same as a late 90s Geo Metro. And, being a prototype, there is not "real world" MPG...just potentially ideal driving.

I like the combination and results though. Stuff it in my insight, please!
  Reply With Quote
Old 01-11-2021, 07:26 AM   #4 (permalink)
EcoModding Apprentice
GreenTDI's Avatar
Join Date: Apr 2020
Location: Belgium
Posts: 226

GreenTDI - '11 Skoda Fabia Estate R3 1.2 CRTDI
90 day: 65.02 mpg (US)
Thanks: 53
Thanked 86 Times in 68 Posts
Very nice concept, of which 50 cars were built. In the next video there is some information about this early VW 3L car - in german - but with some graphs and a test drive that begins at 4:16.
It's quite progressive for that time! 27 hp in normal mode, 40 hp with the supercharger activated. A semi automatic gearbox, start/stop, coasting with engine off, but also emissions were taken into account, with EGR and a particulate filter. We're talking about 1987.

Skoda Fabia Estate R3 1.2 CRTDI
See my thread: https://ecomodder.com/forum/showthre...mpg-38318.html

Last edited by GreenTDI; 01-11-2021 at 07:37 AM..
  Reply With Quote
The Following User Says Thank You to GreenTDI For This Useful Post:
Ecky (01-14-2021)
Old 01-14-2021, 07:05 PM   #5 (permalink)
It's all about Diesel
cRiPpLe_rOoStEr's Avatar
Join Date: Oct 2012
Location: Porto Alegre, Rio Grande do Sul, Brazil
Posts: 10,510
Thanks: 0
Thanked 1,277 Times in 1,131 Posts
A nearly 50% power improvement with the supercharger on. When it comes to particulate filters, makes me wonder how the trapped particulate matter would be dealt with. There were some attempts to use particulate matter on rubber processing in Brazil, but AFAIK it was phased out even before DPF became mandatory on newer buses. Seems like it was just easier to burn the soot off instead of collect it and send it to rubber processing plants...

  Reply With Quote
The Following User Says Thank You to cRiPpLe_rOoStEr For This Useful Post:
Ecky (01-14-2021)
Reply  Post New Thread

Thread Tools

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