I was just curious and wanted to get a general consensus from everyone. What motors usually last longer? Diesel or gasoline?

 

Diesel

 

It depends on the motor, and the maintinance, but typically diesels. Although I know where there is a 1972 chevy pick-up with over 600k on a 350, that's never been rebuilt. Chevy had a contest a couple years back and the winner had over a million documented miles.... I would have to say it's all in how it's taken care of.

 

diesel engines usually last at least twice as long as gas engines one of the bigest reasons for this is the rpms, diesels usually run at not even half the rpms as gas engines....

 

If thats the case, that diesels last longer, then why dont more people use them. They get better gas mileage, have monster torque, and last longer. Sounds like a win, win, and win scenario.

 

parts and cost in general is more expensive, like i said rpms is a big part, so they arnt good for racing, and hp is low where as torque is tremendous. i go to school for automotive technology, and they have diesel tech in the next building i hear how diesel is "better" then gas engines all the time, all i ever say is dont be jealous that my motor isnt scared of 6000 rpms...

 

diesel's tend to run for alot longer than gas engines. but you always have the exceptions. if you look into newer cars, they are coming out with way more diesels every model year. the only downfall, is that around here (FL) diesel is a little over $4 a gallon.
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igotta355Z28 - what school are you going to? i am going to UTI in orlando after i finish my AA. i start UTI on like 1/5/09 (for the automotive).

 

I got to Texas State Technical College Waco Campus.....

 

I agree with the statement that they're more expensive thats true. Being that diesels have to have strongly enforced internals and their exhaust systems have to be heavily modified to meet stringent smog tests. The cost of diesel fuel at $4 is also true here in Cali, but when you have to fill up less often it kinda evens out. The whole bit about racing is bologna too! Look at what Audi has done with their diesel engines at Le Mans. They're blowing the competition away.

 

yes there are some small stroke engines, that are capable of higher rpms, but think about how much that motor cost compared to a comperable gas motor....wow whats with you and diesels anways...u thinking about putting one into your third gen.....i hope not but whatever floats your boat....and gas milage isnt that much better in diesel powered cars......

 

Americans are now facing Ultra Low Sulfur Diesel. Its a lot cleaner burning. And yes, the big three have four cylinder diesels in the R&R phase right now. It wont be too much longer. The new generation of diesels dont smell and run very quiet. I used to work on volkswagons, and they have come a long way. Look to see that trend continue.

 

Im really interested in the new diesel that Subaru is coming out with. Its a flat four diesel, the first diesel in the world in a flat four configuration. I think alot of people are going to shift to diesels soon for the fuel economy.

 

doubt it, maybe because of bio diesel, but the trends are to go twords renewable resources not diesel, and like it was pointed out above diesel gets you a lil better milage but cost more so its about even, most cars within a few years will be hydrogen fuel cell, hybrid electric, and performance engines will probably go twords ethanol, maybe some diesels there...diesels are destined to stay in trucks and a few niche cars..... whats up with all the diesel love in here anyways screw gas milage i want speed and power.....lol these are camaros for god sake milage comes like number 5 on the list of whats important, any higher and maybe yall should be heading twords a rice burner page.....

 

I know that newer vehicles and fuel treatments handle some of this, but I remember that diesel gels at low temperatures, which can be quite the pain if you live in a colder state.

In the US, I think alot of the reason they aren't used that much has a lot to do with both that your standard American doesn't understand much about a diesel engine, and what little they remember about them was the foul smelling smoke belching disasters of the 1980's diesels in cars. I remember seeing a Car and Driver article specificly about that actually.

On the other hand, as mentioned here already, Audi and the Germans seem intent on bringing these motors to the US. If they are willing to educate the public and wait a while, they will probably enjoy some success in that.

 

diesels are only really limited by their structural integrity as opposed to gasoline engine which are limited by their structural integrity and their fuel... because detonation is exactly how they keep ticking along.

there are many 5.9 12v cummins out there pushing 1500hp/2500ft/lbs with nothing more than head bolts and a huge turbo

their downfall is cold weather, initial price, and and that they dont make a dyno strong enough for their torque numbers

 

I think that diesels are under rated. Could you imagine how fast you could tune a Cummins Diesel to run? You would kick major *** at the track! Even a Duramax Diesel! Forget about the Power Stroke Diesel, they arent that great, and as the saying goes "I'd rather be cummin' than strokin'!".

 

RPMS LIMIT U ON BIG DIESELS..... TUNE ALL U WANT THE MOTOR CANT TAKE 5K RPMS they are fun to watch and for a big *** truck they can move but god its a diesel...

 

they can take 5k with ease. though stock its a bit much.

i guess youve never seen a diesel drag truck in action?

awesome.

 

he said tune not rebuild bottom end to take rpms...yes ive seen plenty of *******s at the track put thier diesels on the line and run 14s and 13s even sometimes witch is very impressive for a big *** truck.....

 

also keep in mind some of these 2000+ft/lb engines are getting 17mpg on the highway.

 

what diesel truck has 2000 ftlbs of torque? and this is intresting i just found on a cummins FAQ site

• With the OEM 30 pound valve springs, 12 valve engines begin to float the valves at 3700 rpm
• Destructive torsional harmonic resonance occurs at 4100 RPM
• Crank and rods fail at 5400 RPM (if you make it through 4100 RPM)

 

...stock

 

well yeah stock but i tell ya what if u gave me equal amount of money as u would spend to fix up a deisel i could walk it with a non diesel v8....its just whatever people want to waste thier money on....i think diesels are great for what they are inteded for to make massive torque to pull with....ill have me one someday to pull around my drag car, its like i love hondas for what they are made for.....fuel efficient dependable cars, not sportscars.....so we will have to just agree to disagree casue im out....

 

i dont disagree with you, i was just bored and like arguing.

 

Diesels have been popular over here for decades because of their durability and lower fuel costs, despite their noise, smelliness and gutlessness.
They are even more popular nowadays because the noise & smelliness is mostly history and the turbos make them powerful. There are even diesel powered airplanes!
I once had the pleasure of driving an Isuzu Trooper 2.5l turbodiesel. It would pull a 20 foot trailer up mountains at 60 mph with power to spare for passing, and would get 24 mpg doing that. In sub-zero temperatures it would start with just a flick of the key, no forewarming needed, and would instantly run perfect with no smoke. Great car & engine!
I also tried a 10 years newer Mitsubishi L300 2.3l turbodiesel but it was not as good. It could only pull half as fast uphill, got only half the mileage, and would rattle and cough and smoke on not-so-cold starts even when forewarmed (which was required to make it start at all)..
I'm still not in favor of diesels because they produce lots of ozone, small soot particles, and nitrous oxides, all of which is bad for the environment and asthma and allergies. Diesel owners are also notorious for letting their cars idle when shopping etc..
When a diesel encounters problems pulling uphill you have no option but to go slower. Since their torque falls with increasing rpm there's not much gain in downshifting and flooring it.
The common turbodiesel is completely gutless below 1500 rpm (which can compromise you when pulling onto a road, or into a crossing or a roundabout). You need 2000 rpm to get full power. I recently tried a quite new VW Touran TD, and killed the engine many times when trying to pull away (manual tranny), until I got used to it's complete lack of torque at idle/ low rpm. I never had that issue with the old Isuzu.
On a side note, some years ago there was a bus-strike here in Oslo that lasted for three days. The air got better every day, and on the third day you could even smell flowers & grass around. No-one ever mentions that effect, even if we wintertime have lowered speed limits, & taxes on the use of studded tires, all for the sake of the environment.. Even in Bangkok the air is better than here, but there all the public transport vehicles are required to run on LPG.
Oh, and American diesels.. Maybe great engines, but so rattly & noisy..

 

I had a 85 diesel pu 1/2 ton 6.3, when they built the engine, they used a fuel pump from a ford tractor. They would run for years, but GM didn't want that, so they changed the Governor ring in the pump to plastic. Guess what happens when "injector cleaner, alcohol" is used? Yes the plastic melts and the engine just doesn't run right. There were just too many, short life, expensive parts, to make it cheaper to operate.

BTW instead of the normal 12 mpg 4x4, it was a 20 mpg.

Today a good gas will do that.

 

If there is any doubt that diesels cant be fast let this be a testament... http://www.autoblog.com/2008/01/13/d...he-r8-v12-tdi/

 

Diesels are not popular because they initially failed when they were introduced here in America. They were dirty and had cold start problems, among others. They have had sort of a "bad rap" since then. The new diesels are much much cleaner and are more "friendly" to operate.

The thing with diesels is they are more expensive to make, because they need more material to handle the compression. They are also much heavier.

A diesel engine is more efficient than a gasoline engine (only because a diesel has a high compression ratio). Also, charge of diesel produces more power when burnt than a charge of gasoline does.

 

You dont need to run 5000-6000 rpms in a diesel...thats not where they make power. You need to run 5-6 grand in a camaro since thats where it makes power. In order to make a diesel fast, you would need to run it at the proper rpms, so instead of trying to make it scream, you use gear ratio's that would allow the vehicle to take advantage of the powerband of the diesel. The only reason why a large diesel truck will have such big gear ratios is so it can move weight without a problem, not so it's fast. If the parts and engineering were available, diesels will be able to run just as fast, if not faster than gas cars. I wish there was a wider variety of diesel engines around the US for passenger cars, it seems that you can only get one if you buy a 3/4 ton truck, german car, or old gm diesel junk car. No doubt I would have one if they were affordable. Gas engines do have the ability to last as long though, look at older volvos...200000-300000 miles is just getting it broken in.

In my opinion, diesel will last longer as long as its taken care of. I also think there is a much greater chance for diesels in the future, since they will be able to run on just about anything flammable according to their design. When Rudolph Diesel designed the diesel engine, he actually had intentions for it to be used with other fuels besides fossil fuels. I'm thinking if a company can produce biodiesel so that it's profitable, there will be a huge market for diesel passenger cars since it's a renewable resource.

Well, thats my two cents.

 

Some of you guys are hellbent on reinventing the wheel.

Diesels make torque, they do not make horsepower. Horsepower is torque times RPM (basically). If you want to go fast, there are much cheaper, easier ways to do it than a diesel engine. If you want haul trailers and race cars and equjipment arouind, you use a diesel.

The nature of diesel engines is that they are RPM limited, therefore they can never make good horsepower unless they are making TONS of torque. It's much harder for a diesel engine to make horespower than a gas engine.

A diesel just isnt a good race car engine. The Audi Diesels got quite a lot of exceptions from the rules in GT racing that made their expensive, heavy diesels competitive.

 

haha finally some support.....

 

It's not reinventing the wheel. Diesels have come a long way since 20 years ago. They're not ratty, dirty engines anymore. The title of the forum says "Which Motor Lasts Longer?" The answer: a diesel. Why? Because they are simply better built, they don't need to run high rmps meaning less wear, various other reasons. They will get better fuel mileage than a counterpart gasoline engine, while producing less hydrocarbons, carbon monoxide, and carbon dioxide. As far as hot rodding, diesels have come a long way. Look at the aftermarket for diesel pickups. It's possible to make a 3/4 ton truck run 13's in the quarter all day long with a little work. That would spank a lot of cars out there. With a banks six gun tuner on a 5.9 cummins diesel dodge, it's possible to add around 100 horsepower and 200 ft lbs of torque with just a stupid tuner. To do anything similar to that with a gas engine would require a lot of work. Am I telling people to drop the nearest diesel in their f-body? No. The technology isn't there yet. But one day, it will be.

Now that I think of it, why is this on a third gen tech board anyway?

 

I brought the topic up for a couple different reasons. One, I have been seriously thinking of purchasing a newer diesel vehicle (car or truck). The other reason is that Im an automotive enthusiast and enjoy talking about all types of powertrains and such. Ive also wondered why most people I talk to are either ignorant about diesel performance or just flat out ignore it. But thanks to all of you that have paticipated in this discussion. Ive learned something from everyones input.

 

Thermodynamic analysis:

The Diesel Cycle is actually less efficient AT THE SAME COMPRESSION RATIO as compared to the Otto Cycle (4 cycle gas engine). But most cars run 9:1 compression ratio compared to a diesels 20:1, so that's why diesels are more efficient right now.

It's metallurgy and gas formulas that hold back the Otto Cycle from becoming more efficient. (among other things)

 

One of the reasons the diesels last longer is the fuel. It is more of a lubricant then gasoline, and the soot too.

Diesels hold some of the highest HP ratings of any engines, go look at the big boats.

And what about the turbines?

 

Turbines are far to noisy to put into a car. Besides I think Chrysler tried to do that back in the day, but it wasnt too successful.

 

Non-3rd gen.

Mr. , please. . .