Questions tagged [fuel-consumption]

Use for questions related to fuel economy.

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8
votes
3answers
2k views

Would not allowing my vehicle to downshift uphill be fuel efficient?

Would putting my car in Sport and leaving the transmission in 8th gear at highway speeds (using cruise) be more fuel efficient than leaving it in drive with full auto? I just noticed that while in ...
1
vote
1answer
873 views

Fuel Consumption high

I currently owned a Toyota KDH200. Manfactured year 2006. The Engine is 2KD (2490 cc). (Fuel Type : Diesel) I had an issue with fuel Consumption so I went to a mechanic. He scanned the vehicle (he ...
19
votes
4answers
5k views

At what time of day/temperature should I refuel my vehicle?

I mean, should I refuel my vehicle in the morning? The reasoning is simple, in the morning the temperature is low and the density of the fuel would be higher and I get more energy per litre(or ...
6
votes
1answer
1k views

Can the viscosity of the oil affect gas mileage?

If a manufacture recommends a certain weight of the oil for the engine, lets say 5W-40 and instead 5W-30 was used, would the gas mileage of the engine increase as the piston does not have to do as ...
5
votes
4answers
4k views

How does a real-time mpg display work?

Among other things, I'm a computer science instructor. I'm considering a programming exercise to simulate the dashboard mpg display found on many modern cars. It seems easy enough: monitor the fuel ...
5
votes
1answer
662 views

How to calculate fuel consumption and CO2 emission on flex fuel cars using OBDII data?

Here is the thing: I'm trying to estimate the fuel consumption of cars using OBDII data. It's quite simple if we can treat each fuel and its stoichiometric air fuel ratio separately, but when it turns ...
3
votes
1answer
57 views

Best way to access fuel efficiency data during operation?

I'm looking for ways to track real-time fuel efficiency data while driving, using an app on my phone. Will a Bluetooth OBD adapter generally allow me to do this?
5
votes
2answers
90 views

Fuel economy a reasonable measure of a used vehicles engine condition/reliability?

I have never heard of this, and in Google searching for this, I did not find anything on this. However, it seems reasonable that in the below scenarios, in measuring the condition of a used engine ...
2
votes
2answers
3k views

Changing Carburetor

I am using Vespa P 150 x.It has a is 150 cc engine. The fuel average is not too much good.Some one told me that for batter fuel millage there is a option that I may change my original Vespa ...
7
votes
3answers
638 views

Engine Size and Fuel Consumption (cost of driving Audi TTS)

My boyfriend drives an Audi TTS 08 and recently has told me that it costs £15 just for 22 miles in petrol to see me, that's why I apparently don't see him much. When I confronted him about it, he said ...
5
votes
1answer
1k views

Is it possible that fuel consumption increases after changing an alternator?

I had a fault with my alternator and I went to the workshop where they tested one alternator and it didn't work probably. That engine was shaking and sparking. But then they tried another one and it ...
1
vote
1answer
500 views

2005 Chevy trailblazer 4dr 6cyl 4.2vortex

Headlights went out on the way to work. I realized it is only low beam. High beam works fine, I can't find the fuse to replace it? Also replaced spark plugs because of car missing. I've replaced a ...
-3
votes
1answer
97 views

consumption rate [closed]

I would like to know fuel consumption of the following vehicles per kilometer;- (1) Toyota Hilux (2) Toyota Land Cruiser (3) Nissan Navarra (4) Mitsubishi Canter. If possible I would also like to ...
3
votes
2answers
123 views

Most effective weight reduction in modern cars?

This question forked from another question about budget performance upgrades from another user. Weight reduction came up, and rather than hijack that discussion, I thought I'd start a new one here. ...
10
votes
2answers
999 views

40MPG at 100MPH?

Around 1987-1988 I had a Ford Fiesta/Festiva. I was in the Army and regularly made weekend trips, driving from southern California to Central Washington a trip of about 1200 miles. I would leave in ...
3
votes
3answers
630 views

Air/Fuel ratio at 3%-5% of throttle position (closed throttle)

Question about standard car with ECU controlled injection: Does the ECU still inject some fuel if my engine has higher revs than idle speed and throttle is closed (foot off)? As much as I know (I've ...
9
votes
1answer
5k views

Does leaving the choke closed increase fuel consumption

I ran out of fuel using my outboard engine the other day, when I had checked the tank beforehand and thought I saw plenty of fuel. I had forgotten to open the choke for twenty minutes or so. My ...
3
votes
0answers
86 views

What's the most efficient way to manually hold a specific speed?

I noticed that my new car is by activated cruise controll at lets say 50 km/h handling this speed by displaying an current consume of 1.8~2.4 l/100km, while when I'm trying to find the required ...
3
votes
0answers
145 views

Decreased MPG, clicking sound when pressing accelerator

Over the past week, the MPG on my car has gone down significantly, about 3-4 MPG. My driving habits have not changed. In the meantime, there is a distinct "pneumatic" clicking sound whenever I press ...
4
votes
1answer
126 views

Why does the engine have lesser pulling strength when the fuel in the tank is lesser?

I've noticed a difference that when the fuel in the tank is low, it takes a bit more time for the bike to accelerate to a higher speed than if the fuel tank is mid level or full. Same thing said by a ...
6
votes
3answers
1k views

Tapping into the on-board computer

I'm thinking of replacing my car's radio panel with a custom built Raspberry Pi device, something like this device. However, it's usefulness would be much larger, if I could get information from the ...
4
votes
3answers
3k views

Percent of Air and Fuel used for Combustion

I've had this question for a long time. I know the percent will differ based upon the throttle position and will be either by stoichiometric ratio or rich mixture. The stoichiometric ratio (AFR) ...
0
votes
2answers
3k views

Do Front-Wheel Drive cars consume less fuel than Rear-Wheel Drive cars? [closed]

As physics suggests it's more convenient, and thus less energy consuming, to pull a load than to push it. Having said that in a similar situation when two cars are the same in terms of weight, engine, ...
12
votes
7answers
32k views

Can a car AC unit be run on just the car battery?

This might be a silly question but I was wondering if a car AC unit be run off entirely on battery or alternator? As this could help in Preventing power loss during important times such as ...
6
votes
2answers
4k views

Does starting and stopping the engine lots over a short period of time in a non start-stop car damage anything? [duplicate]

In my 2003 Opel Agila 1.2, I try to save fuel and stop the engine manually (by turning the key) when in traffic or waiting at traffic lights etc. Sometimes when in traffic I can stop and start my ...
6
votes
3answers
2k views

Optimal acceleration for automatic transmission? [closed]

In a car with automatic transmission, what's the best way to accelerate so as to minimize fuel consumption? Assume I'm not going to change the gears manually. Note that I'm also considering non-flat ...
18
votes
6answers
13k views

Will higher octane fuel improve towing power?

According to Will higher octane fuel improve gas mileage? higher octane fuel does NOT notably improve fuel efficiency. Will higher octane fuel, increase power while towing? I looked online and found ...
6
votes
2answers
180 views

How can vehicles run on E?

Sorry if this topic is too open ended I'm new to this site. I am studying engines and how they work and I keep wondering, how do cars with no gas still manage to run for a few extra miles? If you ...
28
votes
6answers
11k views

Do cars consume less fuel when in Neutral? [duplicate]

Imagine we're going down a hill and we're driving a manual car. There are two situations: If I put my car in neutral it will go downhill without any need for the injector to squirt fuel into the ...
0
votes
1answer
6k views

How can I calculate MPG using an OBD-II Device

OBD-II provide following readings Mass Air Flow (PID 0166) Fuel–Air commanded equivalence ratio (0144) Can these be used to calculate the actual fuel consumed? Is the output correct?
8
votes
2answers
919 views

For how long should I idle at a stop?

As I approach a stretch of road that has been single-laned due to roadworks, the sign-flipper spins the sign to STOP. Having been through these roadworks before, I know I'll probably be waiting at ...
1
vote
0answers
177 views

Opel Corsa lite 1.4 2002

After reconditioning cylinder head and skimming. Fitting new hydraulic lifters and rockers, find no compression on engine once oil reaches the lifters compression disappears. Tried reducing length ...
3
votes
1answer
337 views

Can we determine the Cleaning Requirement of Air Filter Using OBD

Many a times, the dealer guy says that the unclean air filter consumes more fuel as compared to clean. So, my question is, is this really related to air filter? If yes, can we determine the case using ...
9
votes
2answers
22k views

Higher than normal fuel consumption - What could be the cause?

My 1997 VW Golf 3 is over-consuming fuel, I use 10 liters for 45km, My mechanic ask me to change the automatic gear-box because it is not selecting gear above gear 3 I change the automatic gear-box ...
3
votes
0answers
101 views

What driving speed gives the best fuel economy? [closed]

If you are running low on fuel in a gasoline powered car I guess driving at a constant speed is best and turning off stuff like the AC would be wise . I suppose keeping the car in a reasonably high ...
8
votes
2answers
702 views

Driving slower at low constant rpms or driving fast to get to destination faster, which saves more gas?

As the question title says. I am a new driver and I understand that driving at higher RPMs can burn more gas faster. However getting to a destination longer would mean you were spending gas at a ...
6
votes
1answer
260 views

Alternative fuel consumption metric to MPG to measure actual engine efficiency?

MPG is all very well and good, considering that most people that are concerned about their fuel consumption tend to want to get as many miles as they can out of it before they need to fill up again. ...
5
votes
2answers
4k views

2008 Toyota Corolla 141 Fuel Consumption Too High

I recently got a Toyota Corolla 141. The petrol consumption is too bad. It does only around 7.5-8 Km/l. Could you please let me know the reason behind this ? I was told that the vehicle is too heavy ...
16
votes
6answers
15k views

What makes two-stroke engines less fuel-efficient than four-strokes?

It is a commonly-held belief that two-stroke engines are less fuel-efficient than four-stroke engines, and some example BSFC figures appear to confirm this as well. But what is it that causes two-...
4
votes
1answer
889 views

Calculating AFR using injector flow rate and mass air flow

Is injector flow rate = Mass fuel flow? If so then AFR = MAF/Injector flow rate. Can someone please confirm this?
6
votes
1answer
626 views

1967 Ford F100 miles per gallon

I plan on getting an 1967 ford f100 and saw that the gas mileage isn't the best on these trucks. The certain truck I have my eye on has a V8 5.8L engine and was wondering if more liters in the engine ...
5
votes
0answers
512 views

What causes more gas consumption - Idling with AC or Heat? [duplicate]

So I have begun doing some research on the effects of idling. So my question is, does idling with the AC or heater on affect how much gas is given off? If possible, please give the percent of extra ...
6
votes
1answer
72 views

Fuel system question

See red arrow in the image. I place fuel additive in my car, all of the additives went into that pipe (in the red arrow image) because i didnt know how to place it. Will it still work? or just a waste?...
5
votes
1answer
2k views

Why does my 2005 Mitsubishi Pajero use excessive amounts of fuel?

I have a Wagon with excessive fuel consumption. It's using 30 litres of petrol per 100 ks. I have seen many mechanics who can't find the problem. I know it has good intake and no exhaust problems. ...
1
vote
0answers
491 views

fuel consumption in CR-V 2007

lately I found my car consuming more fuel than usual,it was doing 8 liters per 100km,then it raised to 12 liters per 100km,I asked its agency to check for the problem,they found nothing unusual,after ...
6
votes
4answers
802 views

Cheap vs Expensive Fuels [closed]

What is the difference between the cheapest fuels in a place like Tesco's and the 'high quality', highly priced competitors? Is there actually any noticeable difference in available power, engine ...
7
votes
1answer
67 views

Gasoline grade manufacturer recommends vs what was used during testing

Toyota recommends to use regular(87) grade of gasoline, but tested cars with the gasoline grade 91(see user manual). Somebody know why they recommend to use grade 87 if they did not tested cars with ...
4
votes
2answers
123 views

What senses/controls how much fuel is spent for a given RPM?

When maintaining a constant speed on the highway whether up, down or flat the engine still has the same RPM (assuming the incline is shallow enough not to require a gear change) - common sense would ...
7
votes
1answer
309 views

Why vehicles use fuel and how can fuel economy be improved?

Why vehicles use fuel? Where does the energy in the fuel go? Vehicle fuel efficiency is continuously increasing. Why is this the case? What technologies car manufacturers are using to improve fuel ...
9
votes
5answers
4k views

Will an old engine have worse fuel efficiency than a new engine?

I have a gasoline-engine car that is four and half years old and has been driven for 60 000 kilometers. I have noticed that the fuel efficiency is not what it was when the car was new. However, I ...