Comment Re:Frankly I Recommend Such Things (Score 1) 687
To counter anecdote: Here in Chicago diesel prices can vary somewhat widely. Now a gal of diesel was usually at a 10% or so premium over the 87 octane stuff. If your near any of the highways (i57, i94, i294, i55, etc), expect a 10-15Â premium on top of that. Diesel was cheaper than gas last maybe 4-5 years ago right around when gas was hitting the $3 to $3.50 mark, though there was a brief time when the economy crashed that it was cheaper than normal unleaded by about 15Â. Now local gas prices are anywhere from $2.45-$2.65, and diesel is usually around $2.55-$2.75.
More on topic though, it sounds like its a pretty cool hack. I've investigated diesels as a potential first car in the past due to the advantages it had at the time like: more torque at lower rpms which is better for quick off the green light but never exceeding 45 mph city driving, no hybrid premium, cheaper diesel fuel, and quietness. I don't know if the last one applies to all new diesels, but I remember reading a car and driver 4-ish years ago about some near-production BMW prototype that when going full out on some random racetrack barely produced more noise than the ambient noise of the track itself (say 3-5 decibels). Contrast this to my 1999 plymouth grand caravan (affectionately known as the big purple monster) with just short of 180k miles, which roars like a aged muscle car that smoked from when it was a sweet sixteen until it had to have its voice box removed and sounds like a brick wall in a wind tunnel at 65+ mph.
Unfortunately however, diesel fuel is not cheaper than gas is anymore (at least where I live). Hybrids have hit mainstream with the Prius, which has brought down the hybrid premium down by maybe 1/5th or so of what it used to be. And last, but certainly not least, varying state environmental regulations have kept most the good diesel cars out of the states. A diesel hybrid could mix up the game a bit, but really only time will tell.