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Post by silverdragon on Mar 5, 2015 7:50:06 GMT
Which is faster, petrol or diesel.
You think I am mad?...
Well, I have had a drive of a "tuned" (If you can call it that) Diesel race engine, and it will scroll your knurd and twiddle with your badgers, 'cos it may scare you.
Not yet, but very soon, diesel may make a come back in Racing.
Touring cars, BTTC, or similar... dont expect a F1 style equivalent.
However, for the purpose of this test, I am splitting it two ways, economy, speed.
Take two similar or identical vehicles, one with |Petrol and the other Diesel power plant, with an output of similar horsepower. One or two HP shouldnt make that much difference...
Set out a small race course, let the driver have a few laps to familiarize himself with the course, and set them off to do 10 timed laps in each vehicle.
Measuring how much fuel each vehicle used.
Drag test.... do the 100 yd sprint.
Onto the roads, and do the mileage test on a gallon of gas, who runs out first....
LANG test, give Adam and Jamie one vehicle each for a month, starting with a full tank, and at the end of the month, see who got the better mileage per gallon, then just to be fair, swap vehicles, to eliminate if Adam is a lead footer compared to Jamie. (Or vice versa..)
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Post by wvengineer on Mar 5, 2015 11:19:28 GMT
In the US, your diesel options are limited. VW has a number of cars with both gas and turbo diesel engine options, but I think the only other car currently with a diesel option is a Chevy Cruze. For the most part your diesel engines are only available on they full size trucks.
To compare diesel to gas mileage is a no brainer. No question who will win the mileage test. Take the VW Jetta and their published secs:
A 1.8L turbo gas engine is rated for 170HP, 25 city, and 37 highway
A 2.0L turbo diesel is rated for 150 HP, 31 city, and 46 highway
However, lets throw the economics in. That is where things get messy. In my area, which has some of the more expensive fuel on the east coast, Gas currently goes for $2.35/gal and diesel is $3.09/gal. With that, the cost per mile for fuel between the two is going to be at best a wash. Last time I ran the numbers, diesel still costs more per mile, not even including the added cost of a diesel engine. I don't know how the numbers would show in California with their high fuel taxes (high by US standards, though still low compared to European taxes)
If they do such a long term test, I want to see both the fuel used and the total cost of fuel. that would tell a lot more.
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Post by kharnynb on Mar 5, 2015 12:40:33 GMT
Oh yea, USA has very different ratio's gas vs diesel...we are the opposite.
95E is currently €1.37/Liter or about $6/gallon. thanks to the oil glut at the moment that is the cheapest i've ever seen it.
diesel is currently €1.30/liter or about $5,50/gallon. cheapish, but nowhere near as much affected by the falling gas prices as gasoline.
The trick here is that taxes are higher on a diesel car, but driving over about 20.000km/year makes diesel cheaper.
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Post by silverdragon on Mar 5, 2015 13:15:12 GMT
You have used published Mileage results.... and I believe them as much as I believe the bieber is a misunderstood good kid...?...
Unless you are in a Swedish laboratory with their rolling road, on a computer, if you are in the real world, and put a spare wheel a full grown driver and his lunch box in, the only place you will get close to that low mileage is if you drive off Beachy head.
(A well known cliff face in Southern England)
Yes the mileage should be better in the disease-al, but could an "economy" engine get close?...
Yes the speed and acceleration on a race should be better in a Petrol, but, can a "tuned" diesel with blowers get a grip of the tarmac and at least scare several buckets of whats good for the roses out of the Petrol competitors...
And thats why I ask for a Horsepower-ed comparison, or torques, because if both engines have the same torques and similar horses, its then just a weight issue as to who gets off the line faster and who can do [X] number of laps the fastest.
10 years ago, I would have said easily the Petrol wins any race and the Diesel gets the MPG ratings.
Now?..
We have economy ve-*hic*-les that claim stupendous mileage, and I have driven a Diesel car that you just wouldnt know was diesel from the inside if you were not told so.
It had a sense of urgency that belied its oil-burning heart...
(I say from the inside, it has the alphabet spaghetti on the outside that advertises the diesel bit.... and the exhaust smell is obvious....)
*hic* in vehicles, these super-light-three-cylinder-micro-mini thungs that **Claim** over 80 to the gallon...
They just dont.
Aint seen one yet that can....
They are a HICcup in the world of transport as they aint anything they is supposed to be, slow and plodderring in traffic, cant manage speed on Motorways at all, and just dont look safe at all with those tiny 8inch wheels and all that....
They will slowly go and all hide in a corner when we finally get to grips with Electric and Hybrid cars, which is coming along nicely as time passes, isnt it?...
If its just down the end of the road in urban traffic to get a small shop (they have minuscule boots) or collecting kids from the local school, why not have a smaller car, as a second family car for light duties, yes, get one, why not, but utilitarian?.. and for long (over 10 mile) distance, useless, uncomfortable and unpopular.
Plus they cant do hills with a load on... I have seen one brewing up at the side of the road as it overheated on one of our hills. (Half way up the Glossop side of Snake pass for any interested...)
Some may say they are mountains, but 2,000 ft isnt exactly the highest of hills is it?...
Plus, I cant physically fold up a six foot plus frame and get me inside one.
Back seats?.. you better have a small family... I cant work out how anyone over the size of a child can get back there... (it was a two door and hatch)
It has always been Diesel for any work horse that needs low end grunt for hauling a heavy van around town and a little extra for some modest long distance where it can just manage to cruise at speed limits, and Petrol for light work, or "Should have been there yesterday" rushes.
Petrol has never been the choice engine for anything that wasnt a car.
Diesel was never for anything that wanted a hurry on.
I believe things have changed.....
I say the myths above need addressing, has diesel caught up with its ability to run a little faster....
Has anyone come out with a petrol engine that can get the same mileage or better than an equivalent diesel.
And finally, if you took the small tinky 3 pot excuse lawnmower engine out of one of those micro-thigumies, and put a small economical oil burner in there instead....
Would you either have a good garden shed heater, or would it be viable as a super-economy diesel runabout.
As for the car of choice...
You Americans do all this "we can customise" boasting....
Get two identical vehicles with fried engines and get two new engines, one petrol, one diesel, and go from there. (Go for two automatics as well if needs be...)
Its not exactly rocket science is it?...
Or is it?...
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Post by the light works on Mar 5, 2015 15:20:59 GMT
simple answers to long questions:
take two identical cars with identical rated (HP) engines, and the gaspot will accelerate away from the diesel, but the diesel will get better mileage. diesels extract more energy from their fuel per gallon, and gaspots are lighter. it is simple maths. the key to the polularity of diesels has always been that the engines, if built and maintained properly, run forever, and will drag anything you hang off the back, even if the earlier models had to gnaw their way up hills.
so what has changed?
diesels can spool up higher, and boost harder. when my dad shopped for his new pickup, I believe the flagship diesel pickup generated under 200 BHP. (I know he commented that his gaspot had more horsepower at idle than the diesel had at redline) mine is 12 years old and lists at 360 HP out of the box.it also revs close to 1000 RPM faster than the older one.
the math that is happening in the US, now, is that diesel often costs as much or more than premium gasoline. this means that when you put it in terms of miles per dollar, in the long term, the gaspot becomes the better deal. cheaper to buy, lighter weight, cheaper to maintain, cheaper to feed.
so yeah, Diesel can be a high performance fuel, and gasoline can be an economical fuel. - if that is what you are looking for.
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Post by GTCGreg on Mar 5, 2015 18:05:13 GMT
the math that is happening in the US, now, is that diesel often costs as much or more than premium gasoline. I don't understand that. Before the bottom fell out of the oil market, Diesel and regular gas was running close to the same price. Now, Diesel is almost a dollar a gallon more than regular. Why didn't Diesel also drop in price? |
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Post by kharnynb on Mar 5, 2015 18:16:15 GMT
I think it has to do with side products and refining.
The main reason that in the EU it was much cheaper before is that the USA always had a lot of leftover diesel.
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Post by wvengineer on Mar 6, 2015 1:15:35 GMT
the math that is happening in the US, now, is that diesel often costs as much or more than premium gasoline. I don't understand that. Before the bottom fell out of the oil market, Diesel and regular gas was running close to the same price. Now, Diesel is almost a dollar a gallon more than regular. Why didn't Diesel also drop in price? Taxes. They have raised tax on Diesel fuel a couple times in the last few years while leaving gas alone. Stick the trucker for road maintenance costs... Back to the cars, Its been a while since I test drive a WV TDI, but once thing I remember is that the TDI had a LOT of get-up-and-go it it. Part of it is the power curve on a diesel is very high on the torque. Taking the Chevy Cruze diesel for an example, The engine may only be rated at 151 HP, but it has something like 264 ft lbs of torque, whereas gas engines, the HP and torque are usually pretty close to each other. At least in the US, in most cases the few diesel cars that are available, the diesel engine is the high power upgrade. With the Jetta you can get a 140HP gas or a 150 HP TDI with a huge amount of addtional torque. THe Chevy Cruze is the same way. You have 138 HP NA gas, a 13 HP Turbo gas with a bit more torque, or a 151 HP diesel with 264 torque. So at least for those, they Diesel will likely win a race and will defiantly win on mileage. |
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Post by GTCGreg on Mar 6, 2015 1:55:43 GMT
I don't understand that. Before the bottom fell out of the oil market, Diesel and regular gas was running close to the same price. Now, Diesel is almost a dollar a gallon more than regular. Why didn't Diesel also drop in price? Taxes. They have raised tax on Diesel fuel a couple times in the last few years while leaving gas alone. Stick the trucker for road maintenance costs... I'm not buying that. Yes, maybe taxes are higher on Diesel, of that I'm not sure. But even with the the higher taxes, in our area, Diesel and regular gas was within 10 to 15 cents of each other. Then overnight, gas dropped over $1.24 while Diesel dropped 15 cents. There was no change in taxes during that time. |
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Post by ponytail61 on Mar 6, 2015 4:10:05 GMT
Taxes. They have raised tax on Diesel fuel a couple times in the last few years while leaving gas alone. Stick the trucker for road maintenance costs... I'm not buying that. Yes, maybe taxes are higher on Diesel, of that I'm not sure. But even with the the higher taxes, in our area, Diesel and regular gas was within 10 to 15 cents of each other. Then overnight, gas dropped over $1.24 while Diesel dropped 15 cents. There was no change in taxes during that time. Diesel is basically the same as fuel oil, so demand is higher in the winter. Especially with the winter you all are having in the Midwest and East. |
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Post by GTCGreg on Mar 6, 2015 4:20:53 GMT
I'm not buying that. Yes, maybe taxes are higher on Diesel, of that I'm not sure. But even with the the higher taxes, in our area, Diesel and regular gas was within 10 to 15 cents of each other. Then overnight, gas dropped over $1.24 while Diesel dropped 15 cents. There was no change in taxes during that time. Diesel is basically the same as fuel oil, so demand is higher in the winter. Especially with the winter you all are having in the Midwest and East. That makes sense. Maybe that's the reason. |
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Post by the light works on Mar 6, 2015 6:12:32 GMT
Taxes. They have raised tax on Diesel fuel a couple times in the last few years while leaving gas alone. Stick the trucker for road maintenance costs... I'm not buying that. Yes, maybe taxes are higher on Diesel, of that I'm not sure. But even with the the higher taxes, in our area, Diesel and regular gas was within 10 to 15 cents of each other. Then overnight, gas dropped over $1.24 while Diesel dropped 15 cents. There was no change in taxes during that time. supply and demand. you don't actually think gas prices are related to the cost of getting oil out of the ground, do you? |
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Post by GTCGreg on Mar 6, 2015 6:19:15 GMT
I'm not buying that. Yes, maybe taxes are higher on Diesel, of that I'm not sure. But even with the the higher taxes, in our area, Diesel and regular gas was within 10 to 15 cents of each other. Then overnight, gas dropped over $1.24 while Diesel dropped 15 cents. There was no change in taxes during that time. supply and demand. you don't actually think gas prices are related to the cost of getting oil out of the ground, do you? No, I don't. But it's the same oil that is refined into gas, Diesel or heating oil. If that base oil price goes down, for whatever reason, then you would think, or at least I would think, all products derived from that oil would also go down. But Ponytail's explanation makes sense. If there is a much greater demand for heating oil, I can see how that could affect the price of Diesel more than gasoline. If this assumption is in fact true, I would expect to see Diesel prices drop considerably this spring when the demand for heating oil declines. We'll just have to wait and see if that happens. Of course, I have no doubt the price of gasoline will skyrocket under the excuse of greater demand caused by summer driving. |
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Post by the light works on Mar 6, 2015 6:27:39 GMT
supply and demand. you don't actually think gas prices are related to the cost of getting oil out of the ground, do you? No, I don't. But it's the same oil that is refined into gas, Diesel or heating oil. If that base oil price goes down, for whatever reason, then you would think, or at least I would think, all products derived from that oil would also go down. But Ponytail's explanation makes sense. If there is a much greater demand for heating oil, I can see how that could affect the price of Diesel more than gasoline. If this assumption is in fact true, I would expect to see Diesel prices drop considerably this spring when the demand for heating oil declines. Will just have to wait and see it that happens. Of course, the price of gasoline could skyrocket under the excuse of greater demand caused by summer driving. my understanding is that every barrel of crude is a certain percentage gasoline, a certain percentage diesel, a certain percentage kerosene, and a few other more or less volatile derivatives. you can tweak the percentages a little in refining, but not that much. Diesel was cheap before every guy in america bought a rod-knocking Dodge/Cummins. then it started working its way up. |
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Post by GTCGreg on Mar 6, 2015 6:35:40 GMT
Diesel was cheap before every guy in america bought a rod-knocking Dodge/Cummins. then it started working its way up. I seriously doubt that had much effect on Diesel fuel demand. Semi's, Buses and larger work trucks are still the largest users of Diesel fuel. These half-pint pick-ups are a drop in the bucket compared to the real trucks. |
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Post by silverdragon on Mar 6, 2015 8:38:26 GMT
the math that is happening in the US, now, is that diesel often costs as much or more than premium gasoline. I don't understand that. Before the bottom fell out of the oil market, Diesel and regular gas was running close to the same price. Now, Diesel is almost a dollar a gallon more than regular. Why didn't Diesel also drop in price? Transport. "Some say" and there is the conspiracy. All commercial transport runs on diesel, that affects the price of a loaf of bread, and the tax that can be put on it, so dropping the price of diesel will significantly drop the revenue that each govt gets on %age of VAT and the like, purchase tax or whatever it is. On Everything that is transported..... Therefore, the fuel companies are being "Controlled" by the Govt on what price they can set on diesel. Of course that will be denied.... |
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Post by silverdragon on Mar 6, 2015 8:41:47 GMT
Diesel and Fuel oil was originally the remains of what could be refined... hence it was cheep....
Now they have better refining methods, and can "crack" the remnants, they can get a better split.
Diesel is not not the same percentage of a barrel as it used to be, as that remainder oil can be converted into something else, with ease...
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Post by the light works on Mar 6, 2015 14:30:34 GMT
Diesel was cheap before every guy in america bought a rod-knocking Dodge/Cummins. then it started working its way up. I seriously doubt that had much effect on Diesel fuel demand. Semi's, Buses and larger work trucks are still the largest users of Diesel fuel. These half-pint pick-ups are a drop in the bucket compared to the real trucks. yeah, but they can't run their rod knockers on regular, and they won't let go of them - so they're stuck paying the price. |
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Post by OziRiS on Mar 6, 2015 20:37:21 GMT
Which is faster, petrol or diesel. You think I am mad?... Well, I have had a drive of a "tuned" (If you can call it that) Diesel race engine, and it will scroll your knurd and twiddle with your badgers, 'cos it may scare you. Not yet, but very soon, diesel may make a come back in Racing. Touring cars, BTTC, or similar... dont expect a F1 style equivalent. Do you follow Le Mans? Audi have been running diesels in that race since 2006. And winning. Peugeot quickly followed and there are rumors that Porche are developing their own diesel version for the 2015 season. After Audi introduced the R10 TDI in 2006 and dominated in every race of that season, the IMSA had to change the rules mid-season to allow other teams to be able to compete. Teams running gasoline powered cars were allowed to strip additional weight off their cars and install a larger fuel tank, because they couldn't keep up. And it wasn't just about fuel efficiency either. Audi set lap records during qualifications, proving that the diesel didn't just get better fuel efficiency than gasoline (although that played a huge part in the 12+ hour indurance races, which was actually Audi's reason for trying it out in the first place), but could compete on speed as well, having been measured at up to 211 mph down a straight in one race, which was faster than any other car that season. After the success of the R10 TDI, Audi entered the R15 TDI, which also did extremely well and last year they entered a diesel hybrid, the R18 E-Tron Quattro, so development continues. So, which is faster, petrol/gasoline or diesel? Depends on who built the car. |
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Post by the light works on Mar 7, 2015 1:14:24 GMT
once you go above a certain level, it's not what's under the hood that counts, it's what's on top of the throttle.
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