Welcome to EM, Owen
The P106, with a 1.5D, is just the car I dream about ecomodding. It's lightweight (compared to new cars) and it can be found without useless options like PS, A/C, electronic everything. Its rear looks like it's just begging for a huge kammback, and a bellypan shouldn't be too hard to make. Those mods should be good for another 10%-20% reduction, on top what you'd get from adjusting driving style.
That is a winner car you have there! You just have to know how to use it. Keep us informed.
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e·co·mod·ding: the art of turning vehicles into what they should be
What matters is
where you're going, not
how fast.
"... we humans tend to screw up everything that's good enough as it is...or everything that we're attracted to, we love to go and defile it." - Chris Cornell
[Old] Piwoslaw's Peugeot 307sw modding thread