54

Torque is the name of the game. High torque is needed to move heavy loads. If comparing a gasoline engine to a comparable diesel engine the diesel will always have higher torque. The higher torque comes from the need for a higher compressing ratio needed for compression ignition. To achieve the higher compression ratio a longer stroke is required. The longer ...


46

No. If anything you'll get worse gas mileage with a full tank because you're carrying a heavier load (more fuel = more weight). What you are most likely experiencing is the top half of the tank is larger than the bottom half (in general terms). In other words, the sending unit (float level) in the gas tank most likely takes longer to traverse the top 1/2 ...


28

I'd suggest there's credence for all of these Your fuel pump overheating if it runs dry Unbeknownst to most, the fuel in the tank cools the fuel pump in most vehicles. The pump sits in a bath of fuel for just this reason. Seems counter intuitive you'd stick an electrical device into something as flammable as gasoline, but it works just fine because ...


27

What you really want to look into is Energy Density. So called "Fossil Fuels" have a very high energy density, which is very important for a vehicle fuel since you have to load it and carry it around with you. This chart shows fuels listed in order of their energy density: So, the main reason we don't use X for fuel and everyone seems to be so in love ...


26

A major, but often overlooked, reason for the dominance of gasoline engines in passenger vehicles is the need for diesel engines in heavy vehicles. A given quantity of crude oil, depending on its composition, will yield a given quantity of diesel, a given quantity of gasoline, a given quantity of candle wax, and specific given quantities of other petroleum ...


26

It's not a problem mixing them. Just start using 95 if that is what the engine calls for. You'll not create any issues doing so. Modern day engines have sensors which can adjust for the fuel. If yours calls for 95, but you're running 92, the engine most likely won't be putting out the power it would on the 95. You probably won't notice a difference in ...


23

While energy density is a rather nice property of gasoline and diesel, it's not the primary driver of their use. Instead, the primary driver is a rather practical one: they're cheaper. On the consumer side of things, we don't tend to notice this, as most places price things volumetricly — so much per gallon. In order to see the "true" price, you have ...


22

Cars are routinely left parked for three to six months or more without running, with no ill effects. I wouldn't hesitate to jump it and see if it'll start. As @BrianKnoblauch comments below, jumping a completely flat battery risks the alternator. The risk can be ameliorated by using a battery charger first, or leaving the jump battery and the to-be-jumped ...


21

To OP’s main question: “Why do heavy vehicles almost always use diesel engines?” Answer: Cost and dependability. Diesel engines are significantly more expensive, but have lifetimes many times greater than gasoline engines. For a commercial vehicle that is on the road all day every day, it adds up to big savings because of the better fuel efficiency and less ...


21

Realistically, if the manual and the manufacturer are stating you should use 87 octane, that's really what you should use. If you purchase more expensive 89, 91, or 93, you are just wasting money. The higher the octane rating, the harder it is for fuel to burn (or ignite). If the vehicle was specified to use 93, then that's what you should buy or you risk ...


17

You "can" use diesel in a gasoline engine. In the sense that it will run, but it will run poorly and smoke A LOT. But the problem with gasoline in a diesel engine is that diesel engines rely on diesel to lubricate various components (diesel is an oil). If you put petrol through these components, it washes away all the lubrication and will cause them to ...


16

In Short its based on low burn rate of diesel plus the longer stroke of the diesel engine. First you must understand the difference between these engines, the diesel works on purely compression of fuel , heating and generating bang to produce power, the gasoline on the other hand is natively twitchy and needs a spark to explode and produce power on its own. ...


14

Are you sure the gas station was open? I recently had the same problem and found that the lights were fully on at the station, the digital readouts on the pumps were glowing, but the place was actually closed and the station owner disabled the pumps. Many stations are closing earlier than expected due to COVID-19. If you are using a credit card to pay at ...


14

The best way to determine the actual fuel consumption is to brim the tank, drive till nearly empty then brim the tank again. Then you have an exact volume of fuel and a specific distance. Repeat over three or four tanks and you will have an accurate fuel consumption figure based on your actual use. The gauge is not linear in performance and not designed to ...


13

Higher octane fuel does not burn as easily as a lower octane fuel. Higher octane fuels are specified where higher compression ratios are present in an engine, or where forced induction (such as turbo charging) is used. By using higher octane fuel where lower is specified, you will create no problems with your engine. It does not (by popular belief) add any ...


13

I would say there are two major reasons. First, the seals and o-rings used in diesel engines can't tolerate the chemical composition of gasoline. They are designed to tolerate the chemical composition of diesel only. Second, the kind of pressure needed to inject diesel can't be tolerated by gasoline. The Chevy Duramax diesel engine has 23,000 PSI in the ...


12

Regulations limit the amount of unburnt hydrocarbons that can be released into the atmosphere, therefore fuel tanks on cars now have to be sealed to stop these emissions. The noise you hear is air rushing into the fuel tank, due to the low pressure caused by the use of fuel.


12

IF - the tank was uniform in its dimensions - vertical sides, etc., and IF - the gauge sender worked exactly in a linear manner, and IF - the gauge responded in that same linear manner, and IF - the sender sent 'tank full' message to the gauge when it was full, then the half-full shown on the gauge would be truthful. However, none of those can be true. The ...


11

Given two engines of similar weight, both operated at their respective optimum efficiency (i.e. maximum mechanical work done per unit of chemical enthalpy in the burnt fuel), you will end up with similar fuel consumption for either engine type. But a Diesel engine will generally offer slightly more power out of this, by giving more torque; that's how it's ...


11

Presumably since you say "92 octane gas" you are not in Europe. The whole topic is a mess, because there are different scales for measuring "octane". The most common scale world-wide is RON, but there is a different scale known as MON which produces lower numbers, and in some countries (particularly the USA, Canada, and Brazil) the numbers on the pump are ...


10

It sounds like you already know why a gasoline engine keeps the fuel/air ratio as close to the stoichiometric ratio as possible, but just for the sake of information for anyone else: The stoichiometric fuel/air ratio is the amount of oxygen required to burn all of the gasoline completely. A "lean" burn leaves some oxygen leftover and a "rich" burn means the ...


10

It is not likely the quality of the gasoline causing the change. The sensors are unable to evaluate the chemical makeup of the fuel. It could be a change in your driving habits, changes in temperature, the vehicle health, tire pressure, etc. I would not be too concerned. The dash indicator is an estimate only. The computer monitors how you drive, current ...


9

You can run gasoline in a diesel motor, but it causes problems. As mentioned elsewhere, when you compress the fuel/air mixture enough, it gets really hot then ignites. With diesel, this is ok, because the fuel burns (relatively) slowly, so it doesn't need to be timed very well. Gasoline, on the other hand, burns really fast. If you consistently ignite the ...


9

You can see the ill-effects of misfueling in this episode by Fifth Gear. They put petrol (gasoline) in a diesel car and vice versa. A summary of the differences between the two fuels: Diesel does not burn as easily as petrol. It relies on auto-ignition under compression rather than spark-ignition to combust. Diesel has a higher AFR value than petrol. ...


9

Gasoline sitting for two years in the float bowl of a carburetor will surely lead to some varnish. The hydrocarbons evaporate from the fuel and oxygen acts as an oxidation catalyst changing the remaining components into other compounds leaving varnish in their wake. Varnish will coat and clog the inside of the carburetor. Float bowl, floats, needle and ...


9

Here is a link from the API (American Petroleum Institute) website. http://www.api.org/oil-and-natural-gas/consumer-information/consumer-resources/staying-safe-pump The article is called Staying safe at the pump. It talks a lot about static discharge among other things as sources of ignition. In most jurisdictions it is illegal to have an engine running ...


8

Definitely air conditioning requires more energy, since heat is, as correctly stated in the other answer "basically free" because it's the waste heat from your engine. According to this study by R. Farrington and J. Rugh of the National Renewable Energy Laboratory (NREL), Current air-conditioning systems can reduce the fuel economy of high fuel-economy ...


8

It stands for Injection as in Fuel Injection.


8

The i is a leftover from the 1970s, when a few companies (BMW and Mercedes, notably) started replacing the carburetor on their petrol engines with fuel injection. The marketing department saw an opportunity (for bragging about the superior fuel management on those cars) and added the i (or E, in Mercedes' case, for Einspritzung, German for injection) to the ...


8

If you have the ability and access to some tools, remove the battery and bring it to your local national auto parts chain ie: AutoZone, AdvanceAuto Parts, Oreillys etc. You may want to call first to see how they are handling this during Covid. They will charge and test the battery to determine its condition generally for free. This will take several hours or ...


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