metrompg.com series | Highlighted on Fuelcons
This further experiment published on metrompg.com delves into a DIY aerodynamics experiment conducted on a Pontiac Firefly (like the Geo Metro a variation of the Suzuki Cultus), aimed at enhancing its fuel efficiency. The author drew inspiration from Phil Knox, who achieved an impressive 28% increase in highway mileage by implementing aerodynamic modifications on his 1994 Toyota T-100 pickup.
The two modifications put to the test were a grille block and rear wheel skirts, both crafted from readily available materials.
The grille block, constructed from cardboard, was designed to enhance both, aerodynamics and cold-weather efficiency. In a previous preliminary trial, it had demonstrated a 3.1% improvement in fuel efficiency (‘Papier mache aerodynamics: +1.5 MPG?‘). On the other hand, the rear wheel skirts, which encased the back wheels within the wheel arches, sought to streamline airflow around the wheels. They were crafted swiftly and effortlessly using cardboard and duct tape. For the experiment, the author conducted a ScanGauge-enabled trial under controlled conditions, maintaining a constant speed with cruise control and conducting bi-directional runs on a defined road segment.
When compared to the control runs (without aerodynamic modifications), the grille block alone resulted in a 2.6% improvement in fuel consumption in terms of km/gal (US) (70.87 vs. 72.70), corresponding to a -2.5% change in L/100 km (5.34 vs. 5.21). Combining the grille block with the wheel skirts yielded a remarkable 5.7% improvement in km/gal (US) or a 5.4% reduction in terms of L/100 km.
The post also explores considerations for crafting more durable aerodynamic modifications and addresses the challenges associated with designing removable wheel skirts.
Source: metrompg.com