This guy really knows his stuff, good work.

Bless your heart and others like ya! I really appreciate folks like you sharing their knowledge. Keep up the good work young fella! FM

Really comprehensive and informative. Thank you for letting the rest of us learn from your talents and knowledge. Great video!

Owning a ram 3500 6.7l diesel, I have been hooked on your knowledge. Keep up the great work! You even taught me about my exaust brake and other things the dealership is clueless about.

Great video on the difference between gas and Diesel engines. Short and sweet and right to the point.Love the engineers facts.Bravo.

Great videos! Where where you 22 years ago when I was a young apprentice! Keep up the great work!

Another fine video to watch. Keep them coming.

Adept Ape, Our Diesel Messiah ! 😁👍 Seriously, great work as usual. You deserve every view, thumb up and subscriber you get. 😎

Your vids are awesome! I'm just getting to know a new Cummins I6 and have been basking in the warmth of diesel fired badassery. Your Cat vids and this help me soak in what that motor really is.

Great video again adept!

Great video, thanks for sharing your knowledge.

nice simply explained video. thanks

Love It!!!!! what an excellent explanation!

Excellent video. I learned what I needed to.

Clear and concise, thank you.

Another great video AA. I think we all can thank Dr. Rudolf Diesel on he's great invention that were all benefiting from. Also great analogy on the internal combustion engines. We did have an engine that ran on diesel, mogas, kerosene and JP-8 fuel when I was in the US Army. We also could mix the fuel but it ran like crap when we did.I believe it was M35A1 on a deuce and a half truck. I want to say Hercules Diesel was the manufacturer. Thanks JSL

nice video thanks for sharing.

without watching i can take a guess as to why. energy density. now to see if im right? love the channel, thanks.

Old video, but good. I had an 82’ Chevy LUV with a 4 cylinder Isuzu diesel. Got over 40 mpg with that thing. The good ole days

great informative vid thx

Great video! How do gasoline injected engines compare to regular gasoline and diesel engines you have explained here

Good stuff thank u

Another thing i would like to add when it comes to the diesel vs gas debate as well is when it comes to tuning/modifying the engines. A diesel engine responds a lot better to mods than what a gas engine does, GM's 6.6 Duramax is an intake, exhaust and a hot & smokey tune away from 500 horsepower where as an LS1 is heads,cam,Intake and a 100 shot of nitrous away from the same power level. (Granted the LS1 is 50 ish cubic inches shy of a Duramax displacement wise)

Not bad. Thank you.

At tickover speed the turbo provides no increase in air volume into the cylinders because it's not spinning fast enough , also when you stop accelerating and start cruising the turbo does nothing. So it's then back to suction to draw in the air on the induction stroke.

RPM range is another cause that diesel engines have better MPG... very nice explanation.

the biggest and main reason is because of the cylinder pressure at TDC. if gas did not predetonate it would get similar gas mileage to diesel. from the calculation of the PV curve of this adiabatic type compression, efficiency of the system increases with compression ratio or equivalent compression ratio (boosted).

Thnks for the wonderful explanation i am gettin into diesal car and i need to know if i will save money in the long run owning a used 07 to 13 vw wagon since they just got sued and it is cheap right now. I am tired of filling up gas and i think its a money pit for my daily driver plus petro is a game that the Gov plays on us! What do u think?

Doc told me to up my calories so now I know what I'm gonna do...

My 15’ 5.7 4X4 TSS DC TUNDRA gets about 17.8 unloaded going down the highway here in Texas. During winter time I get 18. Dads 2007 Bulletproofed 6.0L he gets 22 MPG unloaded down the highway

my honda civic 2.2 i-ctdi gets 57mpg on mormal driving being sensible sticking to speed limits and being smooth 😆👍 but if i drive like a maniac and tear it around the place like i stole it 😈 it gets 40+mpg 😊 unbelivable i love diesels 👌

Modern emission regulations are killing the diesel engine worldwide... So unfortunate, I love everything about diesels

this past July, I drove my Smart Car diesel from Canada to Nebraska checked and double checked: 996 miles: 62.5 U.S. gallon per mile the engine is 3 cylinders, 900cc had lots of power. No problem keeping up with traffic or passing, but I did keep it about 60 mph in an attempt to get the best mpg possible I'll never sell the car - love it.

Correct observations there, although I don't think the comparison between a N/A gas engine and a turbo diesel is on point. Bettter compare N/A to N/A or turbocharged to turbocharged. Cool vid though!

The best way to compare an engine enficency is to compare engines with the same power (Gas and diesel)

You didn't talk about the different ignition sources. Diesels have to run unthrottled because they rely on the heat of compression to ignite the fuel as it is injected into the combustion chamber. If restrict the amt. of air lower compression lower heat no ignition. They are also much heavier. as the combustion event is more violent and really hammers the engine internals such as pistons rods crankshafts ,etc..

Your best answer is to direct you to a library where you will find books that give you a picture type diagram of the OTTO combustion cycle versus Dr. Diesel's cycle. Basically, the OTTO cycle is combustion at constant pressure, whereas the Diesel cycle is combustion at constant pressure. But be careful here as Boyles law that you should have studied in high school physics gets right into the middle of everything.

I bought a new 2016 Canyon 2.8 duramax. I was scared to buy it on the first year. But needed a new truck. Do you know of any issues I should be worried about? Is this motor going to treat me good?

Reasons why diesels get good mpg is due to the viscosity of the diesel. The fuel is just like cooking oil that needs more heat to ignite than gas so refueling is a bit less likely to happen in diesel cars than gasoline cars

back in the early 80's almost all car models had an option for a small 4 cylinder diesel with a 5 speed manual transmission Toyotas Ford escort chevetts and even a Nissan Maxima cause my uncle owned one but for some reason this died out . probably because the fuel got more expensive and early diesels had trouble in the cold starting? not Shure I was only about 6 years old then.

Ya well... when you accidentally put diesel in your pressure washer when mixed with a little gas it’ll run about half choked and man did it have some torque!!

citroen c3 ehdi 2012 1.6ltr 93 hp : 46 Miles per gallon combined. 0-100 in 11.3 seconds. top speed 121 Miles per hour.

Awesome explanation. While talking about foot-pounds of torque you said: "this isn't to say that diesel engines are cheaper." Were you referring to the cost of ownership relative to the same for a gas engine? Sorry only point I was confused.

My c15 is barely getting 5 mpg and it runs great.. Is this common?

Is this the reason why diesel engines take longer (in some cases much longer) to get to temperature than gasoline ? I have an 06 Mondeo 2.0 diesel which you can let idle in winter until the next day and it will not get to 90 unless you drive it. And yes, the car is ok technically - had it triple and double triple checked and both thermostats are replaced with OE ones.

Excellent video. With the advantages of diesel vs gasoline, it's damn unforgivable that more diesel powered cars and light trucks aren't available here in the USA. I've never understood why that is. The EPA wants us to drive fuel efficient vehicles, cars that can drive up to 400 miles before refueling. Unfortunately, they're refusing to allow small displacement diesel engines to be offered.

The real question is, is it more economical to buy the diesel model with it having a higher purchase price, maintenance expense, and fuel prices, vs the gas engine?

I agree with everything but your explanation of the turbo and the pressurized air thing. The turbo is being turned by the exhaust, so the piston on the power stroke that is pushing the exhaust stroke on the other is doing the work of pressurizing the air. You didnt really explain it wrong, just not fully. I think that it would be better to describe the turbo as a method of capturing energy that would otherwise be lost out the exhaust pipe.

Can diesel engines actually run on used motor oil as fuel or vegetable oil?

Fine, for the most part, but there is one thing you did not get quite right. You should have compared a normally aspirated Diesel engine with a normally aspirated Otto-cycle engine. That would have removed one complication with the comparison. You stated that on a turbocharged Diesel engine, the pressure from the turbocharger helps to force the piston down during the intake stroke. Fine, but that doesn't actually help since the turbocharger gets its ability to do that by stealing power from the engine by increasing the exhaust back pressure. The most important reason that a Diesel engine is more efficient, but not the only reason, is that it has no throttle valve and therefore the engine does not waste power sucking in air against the vacuum created by the throttle valve. A very important source of inefficiency with the Otto-cycle engine is the waste of power to suck air in against the vacuum created by the throttle valve. When running at full power, the efficiency difference between a Diesel engine and an Otto-cycle engine is far less because then the throttle on the Otto-cycle engine is fully open and creates no efficiency-robbing vacuum. It is possible to eliminate the camshaft to get perfect valve timing under all conditions by using a computer controlled accuator for each valve. That can eliminate the throttle valve by one of two methods: 1) It can control the power by opening the intake valve only briefly when full power is not required. That way, the vacuum created when the intake valve is closed will help pull the piston up again during the early part of the compression stroke thereby recovering the power lost by creating the vacuum. Or, 2) It can control the power by delaying closing the intake valve until way past bottom dead center when full power is not required thereby not creating a vacuum but letting air escape from the cylinder until the valve closes. Either of the two methods can control the power with no throttle valve thereby eliminating the inefficiency caused by the throttle valve. The reason this is not been implemented is that it is very costly, but it has been successfully tested. In addition to greatly improving the efficiency of the Otto-cycle engine, it can also increase power and flexibility by having ideal valve timing for all engine speeds.

Your voice sounds like Cleveland from family guy.

A unit of diesel fuel (gallon, gram, or bucket) contains more energy than the same amount of gasoline. Is it so surprising that you would require less higher energy fuel to do the same work as the less energetic fuel?

i just came in to your video's, love them! but can you (for fun) give a mechanical diesel engine a bit more power and rolling coal (i know its stupid but i just want to know lol)

I never knew there were "calories" for fuel volume. I've learned the fuel to air ratios are a lot different to combust. Correct me if I'm wrong; diesel combusts at a 300:1 ratio and gas is 60:1 fuel to air... ?

So a turbo in a gasoline vehicle it gets extremely hot and needs its own active cooling. So if the thermal efficiency is better in the diesel, does the turbo not get as hot? If so do these turbos last long?

Sterling engine can run on gas or diesel

what would be then the advantage of choosing a gasoline engine, besides price?

So what's the difference between diesel mechanics and auto mechanics?

hey adep ape i have a marine diesel engine 3406E i was wondering what are the cause of high oil pressure

I have question for you that is bugging mi for long time. Why naturally aspirated diesel engine makes much less power for same displacement than naturally aspirated gasoline engine. for example 1.9SDI (VW engine) 65HP vs 1.6FSI 115HP (Audi engine)? It is even stranger because diesel have more energy per gallon than gasoline.

How about comparing new diesel engines vs old non egr diesel engines. New diesel engines make more power on average, but also get less mpg. Example VW TDI engines.

I drive a diesel car...love it

doesn't gas engines run at the high 20's in thermal efficiency while diesels run in the mid 30's and the huge diesels that are in ships run closer to 50%? Also isn't the maximum theoretical thermal efficiency of an internal combustion engine 64% thermal efficiency?

If i remember the old cat d8 14a will run gas/diesel. starts and warms up on gas then you switch to diesel.

Why don't they make over built gas engine that run at crazy compression so they stay strong like the diesels but run more efficient?

I think that BTU's, not Calories are the correct measurement for combustion efficiency comparison ??

On the truck engine put in your car. Of course it won't get good mileage. Higher horsepower engine=lower mpg. The newest thing to come out is LNG or CNG engines. These engines burn really inexpensive fuel (Here gas is about $3 to a gallon, and LNG/CNG are about $1.3 to a gallon). However, LNG and CNG have much fewer calories per gallon, about 1/2 as many as gasoline. Therefore, a tankful will only go about half as it would on gasoline. A lot of people don't like diesel, because it's "more expensive." But, they forget about "more efficient."

The same model equipped with a 3-liter gasoline engine will always be thirstier than a 2-liter diesel one. Diesel engines will most of the time be more fuel efficient when compared to same capacity gasoline engines. However, the economy of a 3-liter diesel engine will often be similar to that of a 2-liter gasoline engine. It's hard to understand why didn't you compare same capacity engines. Maybe I'm missing something. Edit: Sorry! Should have watched the whole video before playing the smart-ass number.

There is a major aspect between Diesel and spark ignition engines that is very deserving of detailed discussion and that is spark ignition engine's combustion propagates by flame front from the spark source. A compression ignition engine detonates its individual fuel particles everywhere. There is no traveling ignition flame. Detonation engines as a scientific topic implies the shockwave travels faster than the speed of sound which is suppose to be more efficient than simple gas expansion in rocket engines. This topic, with the available information commonly available, is frankly a bit bazar. The detonation process in a Diesel engine may provide much higher efficiencies than the spark ignition burn process. In heavy duty over-the-road Diesels the need for a powerful reliable dynamic brake provided by the Diesel Jake brake makes the Diesel not realistically replaceable by spark ignition engines. There are many fuel markets today where a heavy duty high efficiency gasoline engine might be cheaper to fuel than a Diesel. There are no heavy duty gasoline large displacement low reving engines with replaceable cylinder liners and such. Nothing that is comfortably on the market. The the high reving Ford V10 OHC gasoline medium duty gasoline truck engine is the closest example I know of. That appears to be a 300,000 mile engine.

I'm looking to buy an older school or shuttle bus could I get your opinion on the best engines please? THANKS

The differences end up washing out in the price difference at purchase time and the price of fuel. If diesel fuel and gasoline were priced the same, then the savings would make purchasing a diesel vehicle justifiable.

One small nit, sucking vs turbo efficiency, the energy to drive the turbo isn't free but comes from exhaust gas. One way or the other the engine is working to pump air through the cylinders. Gas or diesel, turbo's improve torque. But with turbo's the more the boost the more the power, so it is kind of a mistake to even bring them up. What I would like to know is why are manufacturers like Porsche and Ferrari so keen on high-revving motors over high-torque low rpm engines? Because they sound like F1? So why are F1 engines all high-rpm? (I know, because…. rules…)

Why can't they control a throttle on patrols with the injectors like Diesels?

Compare the 2.7 liter F-150 EcoBoost to the 3.0 liter Ram 1500 EcoDiesel and you'll see that there's no benefit to the diesel. The diesel costs more to fuel, has greater CO2 emissions and the EcoBoost has 85 (yes, 85!) more hp. Same thing happens if you compare the 2014 base model Accord to the Chevy Cruze diesel, the diesel costs more to fuel, produces more CO2 and has less power. Same thing went for the Golf TDI and the Honda Civic, except they were equal in power output. I could go on and on, there's just no benefit to diesels.

Question! Are diesel engines 2 stroke? where gas are 4 stroke.

explain this, a 7.3 idi gets 30mpg hauling a trailer with no turbo. but a 7.3 powerstroke gets 11mpg hauling the same trailer. the idi non turbo gets so almost 3x better fuel economy than a 7.3 powerstroke does. so is the your turbo suggestion false? they both have 3.73 rear end, both have a 5 speed. both f250. same exact truck. the difference is the non turbo gets 3x better fuel economy.

Too bad diesel gets a bad rep for being dirty. Alot of countries in europe are banning diesel engines because of pollution. Eventually they want to get rid of gas too. That will force the governments to give us alternative fuels we've already had for decades that are less polluting

3:09 except for a deuce and a half

TDI 4 Life

I disagree with a few things:1. A long stroke does NOT make greater torque. The low RPM of a long stroke engine is determined by the safe mean piston speed.2. You cannot compare turbocharged diesels with naturally aspirated petrol engines.3. The diesel engine's efficiency at part-load is due to its running lean, while a petrol engine has to maintain a near-stoichiometric air:fuel ratio. The petrol engine accomplishes this by throttling the air in the intake, which causes severe pumping losses.4. An efficiency of 45% is a bit high, even for a turbodiesel at torque peak. I don't even think a gas turbine is that efficient. A turbodiesel has a peak efficiency of closer to 35%, and a petrol engine closer to 27%. Of course, it is important to state the measure of efficiency. I base my number on an isentropic efficiency, which works relative to absolute temperature and absolutely lossless and reversible processes. Maybe you use a different measure of efficiency.Great show, keep up the good work.

If gasoline combusts at a lower temperature,why not run a higher compression ratio and inject the fuel just before top dead center like in a diesel? Wouldn't this give you more torque?

I nvr use milk in my diesel...

Why don't petrol engines use some type of governor to control the throttle

Multifuels run on this concept... but they are super inefficient.

And the age old question why gas engines rumble and diesel engines pop.

Deisel engines run slower rpms therefore burn less fuel diesel engine 3 thousand rpm max gas engine 6 thousand rpm max

This makes diesel better? What are the disadvantages of diesels?

$

diesel for its injection system

I like the videos but try to shorten them up

You skipped the emissions part...

you italian or what?

My fiance and 1 both own dodge rams same year's 2005. Mine is a cummins his is gas. We filled up in kansas at the exact same times with same size gas/feul tanks and both have no after market mods. We both traveled from kansas to AZ and has milage for both are almost the same. Everytime we filled up the gas /fuel needles are in the exact same position in both trucks. There is absolutely zero difference in feul milage in gas and diesel. Unless you have actully done this comparison on a road trip with 2 identical situations just one diesle and one gas then your spewing crap. I did this half way across the country with identical driving and load situations.

what about turbo gas engine more air more fuel bigger bang more hp. just asking

I used diesel to light a bonfire and it burned way longer than gas

Diesels rock, a german invention...

Damn I’d be fat af if I drank diesel

Obey acts 2:38

6 minutes of waffle before you actually hit on the main reason, a petrol (gas) engine runs a throttle which is virtually shut when the car is cruising along. This means that the volumetric efficiency (VE) is low, the pressure in the combustion chamber before the plug fires in low which as a direct result on the peak cylinder pressure, in other words it is also lower than ideal. A diesel engine is not generally throttled (but some now have turbulence plates), the engine is only controlled by the amount of fuel being injected, it always operates at least 100% VE and generally more due to the turbo. The peak cylinder pressure is much higher because of this and it is this pressure above the pistons that produces torque. The 'less friction' reason and most of the other stuff is so minor that it is not even worth mentioning. What we need is a petrol engine that runs at 100% VE (or more) that is controlled by fuel only but this is not really possible because if you lean the mixture off too much in a petrol engine it simply won't ignite. (Lean mixtures have other issues too). If we could fill the cylinder with fresh air then somehow inject an air/fuel gaseous mixture in at around 14:1 ratio just around the spark plug and use this to control the engine that would work. We would then have a petrol engine that would have the MGP of a diesel. Unfortunately it is easy said than done! Whilst we are at it fully variable valve timing along with a variable compression ratio would be nice!

Cars burning calories im dead