# Why do people buy diesel cars? **URL:** \ **Category:** Factual Questions\ **Created:** [August 16, 2005, 5:52pm UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299 "2005-08-16T17:52:26Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![mswas](https://avatars.discourse-cdn.com/v4/letter/m/e99b99/32.png) [@mswas](https://boards.straightdope.com/u/mswas)\ **Post date:** [August 19, 2005, 6:39pm UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299/41 "2005-08-19T18:39:52Z")
I might be wrong, but I also thought Diesel engines were better for heavy load type situations. Good for pulling heavy weight and such. Biodiesel is more expensive than regular diesel because of the way it is produced. Biodiesel in America is largely a monopoly of the soybean industry looking to find another way to sell their product. This is a very expensive way to produce it. However, for the same reason you can run a diesel engine off of filtered vegetable oil, you can also make biodiesel out of the same reclaimed grease. I know of a couple of different biodiesel manufacturers that are tooling up to produce it this way. My friend is trying to get his VC together so he can get his refinery together in Brooklyn. [http://www.tristatebiodiesel.com/](http://www.tristatebiodiesel.com/) This form of manufacture will significantly lower the price of biodiesel well below that of petro-diesel and possibly even gasoline. The economics of it are going to be proven very shortly because of the price crunch on oil due to the oil land grabs as well as the fact that oil refineries in America are deteriorating. It’s a really good way to reclaim the diesel, and while it hasn’t yet been proven on a large scale operation that I know of, the figures that I’ve seen for the cost of manufacture from waste grease are very promising. One of the ironies of it however, is that as it becomes more widespread it will destroy the underground hippy economy that has allowed hippies to make cross-country trips for negligible cost over the past ten years. Also, biodiesel from waste grease smells like French Fries when it burns. 😉 Erek ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 19, 2005, 7:15pm UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299/42 "2005-08-19T19:15:46Z")
One other advantage of diesel cars is that if you’re driving in the vicinity of a radio astronomical observatory, a diesel car, without spark plugs, will produce far less radio noise than a gasoline car. OK, so that’s usually not very relevant for most folks, but I still get a kick out of the sign at the entrance to Green Bank Observatory, with a picture of a spark plug with the interdit circle-and-slash over it. ---
**Author:** ![Jake4](https://avatars.discourse-cdn.com/v4/letter/j/bc8723/32.png) [@Jake4](https://boards.straightdope.com/u/Jake4)\ **Post date:** [August 19, 2005, 7:53pm UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299/43 "2005-08-19T19:53:24Z")
What, exactly, are the radio frequencies that spark plugs emit? That is one fascinating piece of trivia. ---
**Author:** ![Rayne\_Man](https://avatars.discourse-cdn.com/v4/letter/r/df705f/32.png) [@Rayne\_Man](https://boards.straightdope.com/u/Rayne_Man)\ **Post date:** [August 19, 2005, 9:38pm UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299/44 "2005-08-19T21:38:24Z")
When I worked in the natural gas industry we were allowed to drive diesel cars on sites were petrol ones were banned , also because of the spark-plug issue. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 19, 2005, 10:25pm UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299/45 "2005-08-19T22:25:11Z")
> [@](#): > > What, exactly, are the radio frequencies that spark plugs emit? Well, that’s part of the problem… If they emitted a few exact frequencies, they’d be easy to filter out, but as it is, they’re pretty broad sources of white noise. The spectrum of a spark plug must still have some peak, but I’m not sure where it would be… At a guess, I’d say it’d be in the vicinity of the frequency corrosponding to the width of the spark gap, in the microwave range, but don’t quote me on that. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [August 20, 2005, 1:09am UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299/46 "2005-08-20T01:09:32Z")
> [@Colibri](#): > > Pardon the small hijack, but what are the factors that caused diesel’s price to go up so much relative to gas in the US? To a large extent- taxes. Gas is usually taxed MUCH higher than Diesel. Good Diesel- low sulphur version (which you may not be getting in Panama)- should be more expensive than Gas. However, usually Gas is taxed higher, as trucks use diesel, and so does farm engines. That last is why AG diesel is cheaper here in the USA- it is taxed very low as a subsidy for farmers. For years, there were very few non-commercail/farming vehicles that used diesel, so it was all taxed less. But with the rise (a decade or two ago) with passenger-car diesels, that went away. Note that there has been some movement to end this “subsidy”, and farmers using it in highway vehicles is one reason. ---
**Author:** ![roger\_thornhill](https://avatars.discourse-cdn.com/v4/letter/r/d9b06d/32.png) [@roger\_thornhill](https://boards.straightdope.com/u/roger_thornhill)\ **Post date:** [August 20, 2005, 1:42am UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299/47 "2005-08-20T01:42:29Z")
Asked my brother-in-law this question on holiday and his answer was 1) cheaper to run (diesel in Europe is cheaper than petrol), 2) cheaper and easier to maintain, and 3) longer engine life. ---
**Author:** ![mike1dog](https://avatars.discourse-cdn.com/v4/letter/m/ba9def/32.png) [@mike1dog](https://boards.straightdope.com/u/mike1dog)\ **Post date:** [August 20, 2005, 2:31am UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299/48 "2005-08-20T02:31:10Z")
If you’re thinking of buying a diesel Passat instead of a gas burner, when you figure your costs, don’t forget that it costs about one thousand dollars more than the gas burning Passat. It’s all academic anyway. In 2007, the new emissions regulations will start, and the automakers haven’t found a way to pass the new regulations. They may talk about urea catalysts, and low sulfur fuel (even more than diesel is now), but there’s no proof they’ll work. Since the market for diesel cars is so small in this country, they’ll probably die out again. ---
**Author:** ![hlanelee](https://avatars.discourse-cdn.com/v4/letter/h/3bc359/32.png) [@hlanelee](https://boards.straightdope.com/u/hlanelee)\ **Post date:** [August 20, 2005, 9:59am UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299/49 "2005-08-20T09:59:32Z")
> [@DrDeth](#): > > To a large extent- taxes. Gas is usually taxed MUCH higher than Diesel. Good Diesel- low sulphur version (which you may not be getting in Panama)- should be more expensive than Gas. However, usually Gas is taxed higher, as trucks use diesel, and so does farm engines. That last is why AG diesel is cheaper here in the USA- it is taxed very low as a subsidy for farmers. > > For years, there were very few non-commercail/farming vehicles that used diesel, so it was all taxed less. But with the rise (a decade or two ago) with passenger-car diesels, that went away. > > Note that there has been some movement to end this “subsidy”, and farmers using it in highway vehicles is one reason. Fuel for off road use is dyed. You don’t want the Transportation Police (DOT) to take a sample of your fuel that is red. There is a stiff fine for using red fuel in a highway vehicle. At the officer’s discretion, usually if he wants to be a dick, he can lock down your vehicle until all of the fuel is off-loaded and replaced with fuel that has been taxed for on-road use. I do not know if the Transportation Police will stop a passanger vehicle to check fuel, but it wouldn’t suprise me, if the officer really wants to be a dick. ---
**Author:** ![Rayne\_Man](https://avatars.discourse-cdn.com/v4/letter/r/df705f/32.png) [@Rayne\_Man](https://boards.straightdope.com/u/Rayne_Man)\ **Post date:** [August 20, 2005, 10:06am UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299/50 "2005-08-20T10:06:25Z")
That is the same situation here in the UK. Red diesel , intended for farm use and boats is much cheaper , because of lower taxes. Customs and Excise officials will make spot checks of road vehicles to see if they are using this stuff. One favourite target are trucks which are transporting sugar-beet from farms to the processing factory. I suppose they have the perfect opportunity to get a top-up from a friendly farmer while they are loading the beet. ---
**Author:** ![Pushkin](https://avatars.discourse-cdn.com/v4/letter/p/ee59a6/32.png) [@Pushkin](https://boards.straightdope.com/u/Pushkin)\ **Post date:** [August 20, 2005, 3:59pm UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299/51 "2005-08-20T15:59:06Z")
> [@Rayne Man](#): > > Customs and Excise officials will make spot checks of road vehicles to see if they are using this stuff This is especially rampant near the border here in Northern Ireland. I heard one tale about a woman pulled over for a spot check whose car was filled with agricultural diesel. Her car was seized on the spot and she had to call her hubby who came down in his jeep. The police thought they may as well dip his jeep’s tank, guess what they found inside 😉 ---
**Author:** ![Enola\_Straight](https://avatars.discourse-cdn.com/v4/letter/e/dec6dc/32.png) [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)\ **Post date:** [August 20, 2005, 4:45pm UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299/52 "2005-08-20T16:45:59Z")
> [@Schuyler](#): > > Back to the **OP** , but it’s my sense that the primary reason to run a diesel in the U.S. is economy - IIRC (can’t find a link) Car and Driver went cross-country in a diesel volkswagen without stopping for a fill-up; of course, they filled the back of the car with extra tankage and transfered fuel on the go. 😛 I seem to remember this too. They used a diesel Dasher, IIRC, with tires over-inflated to 50 lbs/sq.inch. ---
**Author:** ![Balthisar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/balthisar/32/2825_2.png) [@Balthisar](https://boards.straightdope.com/u/Balthisar)\ **Post date:** [August 20, 2005, 5:45pm UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299/53 "2005-08-20T17:45:49Z")
So is it illegal to die on-road, legally purchased diesel red? That’d be damn good explanation for why you have red diesel in your car. You’ve got to do something to catch the syphoning, fuel-stealing thieves, right? ---
**Author:** ![hlanelee](https://avatars.discourse-cdn.com/v4/letter/h/3bc359/32.png) [@hlanelee](https://boards.straightdope.com/u/hlanelee)\ **Post date:** [August 20, 2005, 9:09pm UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299/54 "2005-08-20T21:09:22Z")
> [@Balthisar](#): > > So is it illegal to die on-road, legally purchased diesel red? That’d be damn good explanation for why you have red diesel in your car. You’ve got to do something to catch the syphoning, fuel-stealing thieves, right? I would like to be in court when that defense is used. I know at least one magistrate that would likely add on jail time for wasting the courts energies. ---
**Author:** ![Enola\_Straight](https://avatars.discourse-cdn.com/v4/letter/e/dec6dc/32.png) [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)\ **Post date:** [August 21, 2005, 7:17am UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299/55 "2005-08-21T07:17:07Z")
One could awlays say: “But, Your Honor/My Lord, I only mixed a quantity of automatic transmission fluid into my fuel: its a high detergent oil that is capable of cleaning the deposits on my injectors”. ---
**Author:** ![Rayne\_Man](https://avatars.discourse-cdn.com/v4/letter/r/df705f/32.png) [@Rayne\_Man](https://boards.straightdope.com/u/Rayne_Man)\ **Post date:** [August 21, 2005, 11:02am UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299/56 "2005-08-21T11:02:59Z")
Some quotes from the motoring section of today’s _Sunday Times_ reviewing the new Jaguar XJ powered by a 2.7 litre V6 diesel engine:- I_n the Jaguar, not only is the engine barely audible at steady motorway cruise but even during hard acceleration the extra sound is no more than the multi-cylinder hum you’d hope for in a car such as this._ \*The result is so quiet you have to concentrate to hear the difference ( from a petrol engine) . Even the growl is only detectable when the engine is stone cold . Once under way nobody would ever know. \* The fuel consumption is 35 mpg , 0-60 mph is achieved in 7.8 seconds, and 50 to 70 mph in 4.3 seconds. All this with a six-speed automatic gear-box So quite a car . The reviewer reckons that with this performance, most XJs bought from now on will be diesel powered. ---
**Author:** ![Mr.Slant](https://avatars.discourse-cdn.com/v4/letter/m/c57346/32.png) [@Mr.Slant](https://boards.straightdope.com/u/Mr.Slant)\ **Post date:** [August 22, 2005, 5:44pm UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299/57 "2005-08-22T17:44:26Z")
> [@Enola Straight](#): > > One could awlays say: > “But, Your Honor/My Lord, I only mixed a quantity of automatic transmission fluid into my fuel: its a high detergent oil that is capable of cleaning the deposits on my injectors”. Common misconception. ATF is _not_ highly detergent compared to modern run-of-the-mill API SL/SM motor oil, and nowhere near as effective as any number of products marketed for this cleaning purpose including Redline 85+ Diesel Additive, Lube Control Distributor’s Fuel Power FP60 or Power Service’s “Diesel Kleen +Cetane Boost”. ---
**Author:** ![Gary\_Robson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gary_robson/32/3448_2.png) [@Gary\_Robson](https://boards.straightdope.com/u/Gary_Robson)\ **Post date:** [August 22, 2005, 7:42pm UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299/58 "2005-08-22T19:42:16Z")
> [@hlanelee](#): > > I do not know if the Transportation Police will stop a passanger vehicle to check fuel, but it wouldn’t suprise me, if the officer really wants to be a dick. It’s more of a problem out here in farm/ranch country. I haven’t heard of the highway patrol doing random checks of diesel autos, but they do sometimes target trucks that look like farm/ranch equipment being driven on-road, and they’ve been known to do random stops on diesel motorhomes. It’s not the officer “being a dick,” by the way. Gas and on-road diesel are taxed to pay for highway maintenance. If you’re driving a diesel on the highway and using off-road (dyed) diesel, then you’re not paying your fair share of the highway maintenance. ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [August 22, 2005, 7:44pm UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299/59 "2005-08-22T19:44:28Z")
So this is why I sometimes see trucks with FARM on their license plates? ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [August 22, 2005, 9:49pm UTC](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299/60 "2005-08-22T21:49:46Z")
> [@Sunspace](#): > > this is why I sometimes see trucks with FARM on their license plates? Very likely. Laws will vary by region; in some, you’re allowed to drive on roads but must be within X miles of home, may not drive at night, etc. [Previous page](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299.md?page=2) [Next page](https://boards.straightdope.com/t/why-do-people-buy-diesel-cars/317299.md?page=4)