Article: ecomodding a vanilla Renault production sedan... efficiency up 19%

[MetroMPG]

Some very interesting details in this article in the list of peformed mods.

The net effect was reduced CO2 emissions from from 120g CO2/km to 97g / km - putting it in the same league as a Prius. (Though it should be noted: they are not exactly comparable vehicles.)

Renault Introduces Logan Renault Eco2 Concept at Challenge Bibendum; Taking a Production Car from 120g CO2/km to 97g

Powered by a 1.5 dCi (63kW/85hp) engine which runs on B30 biofue1, Logan Renault eco2 Concept incorporates a variety of technical enhancements and innovations, all of which are paths for future vehicle development at Renault.

The powertrain is based on the 1.5 dCi (85hp) engine launched at the end of 2007 and homologated at 120g CO2/km. The final drive ratio has been lengthened 8% to reduce fuel consumption while ensuring a level of mid-range acceleration that is suitable for ordinary use. This enhancement enabled a saving of 4g of CO2/km.

Renault also re-calibrated the injection system by introducing seven-hole nozzles (instead of five as is the case with production models) and widening the piston bowl for enhanced fuel spray and combustion. This modification produced a saving of 5g of CO2/km.

Finally, by optimizing the play between certain moving parts and using low-viscosity lubricants (5W20 plus additives instead of the standard 5W30), Renault reduced internal engine friction. The gear oil is also less viscous. This work helped cut CO2 emissions by a further 2g/km.

There's much mre, including the list of several aeromods, LRR tires selection, steering geometry setup & other drivetrain tweaks.

The sum of all the work that went into Logan Renault eco2 Concept achieved record low CO2 emissions of just 97g/km (NEDC combined cycle) equivalent to fuel consumption of 3.8 liters/100km (62 mpg US).

Furthermore, the extra-urban phase of the NEDC driving cycle returned UTAC homologated fuel consumption of just 3.4 liters/100km (69 mpg US), equivalent to CO2 emissions of 88g/km.

Definitely worth a read:
Green Car Congress: Renault Introduces Logan Renault Eco2 Concept at Challenge Bibendum; Taking a Production Car from 120g CO2/km to 97g

[MetroMPG]

Here's the total list of mods they did, culled from the GCC article:

• final drive ratio lengthened 8% (reducing consumption 3.3%)
  .
• re-calibrated the injection system and widened the piston bowl for enhanced fuel spray and combustion (4.2%)
  .
• optimized tolerances, low-viscosity lubricants in engine & transmission (1.7%)
  .
• aeromods: front bumper lower dam/splitter; rear pan; revised grille intakes; wheel spats; rear deck lip spoiler; Mitsu-style VG's on the trailing edge of the roof ("a particularly effective solution on three-box cars"); lowered ride height (total of aero savings: 4.2%)
  .
• Michelin Energy Saver 185/65R15 low rolling resistance tires (1.7%)
  .
• low friction rear bearings (0.8%)
  .
• front alignment setup, and "work on the running gear" (2.5%)
  .
• lower voltage alternator (12.8 vs. typical 13.5) with smart on/off control, plus changes to "energy-hungry parts" (3.3%)

[MetroMPG]

They then went and drove this car in the fuel economy challenge at the Michelin Challenge Bibendum and pulled off 2.72 L/100 km (86.5 mpg US) over 172 km.

"The lower result resulted from the driver’s use of the Gearshift Indicator and highlights the importance of the eco-driving factor, according to Renault." (via GCC)

I would say so! On top of the mods, the driving style reduced consumption a further 22% (down to 71g/km CO2) from the original production car's rating.

[MetroMPG]

Oh, and the Renault driver/team took 2nd place overall in the "prototype" category.

Interesting list of vehicles in the results: PDF of Rally results from Michelin

[SVOboy]

Some of these things are very reminiscent of the design of the Civic VX. Sometimes I wonder why manufacturers don't sell ecomodded types of normal cars more often...

[MetroMPG]

I guess because people don't buy them. I recall reading that the VX sales represented about 5% of the Civic total; the Metro XFi made up about 10% of total Metro sales.

But times are changing. More awareness, higher fuel prices...

[SVOboy]

I guess we are seeing this in part with the move to hybrids. I just wonder how much some hybrids are still lacking in these same departments.

[jwxr7]

I just read about this in my new issue of automotive engineering international and had to make sure it was brought up on this forum. Looks like I'm behind the times a little .

I like how they listed the impact of the ecomods they did .

[Jyden]

An interesting car - funny though, that all the engineering, engine tweaks etc is given attention, and only light modifications in the aerodynamic department.....

More work on the areodynamics could have yielded even better results.

For instance I see some big grills on the front of that car

[thatguitarguy]

Don't know that I've seen B30 biofuel widely available on this side of the puddle. Nor have I seen many Renault's.

Maybe the Civic VX and the Metro XFi weren't big hits in the USofA, but similar cars seem to be popular in other markets. The small diesel powered cars over here do seem to be popular and hold their prices pretty well, but we don't have nearly the number of choices that the Euro's do.