Questions tagged [fuel-consumption]

Use for questions related to fuel economy.

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2
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1answer
24 views

Why is fuel going down quicker than expected giving miles driven?

Given the pandemic lock downs and such I've been using my car less, maybe 2 times a week and when I do drive it is for short drives, 5 miles or less usually. But it seems like each time I get in my ...
1
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1answer
72 views

Potential for failing PCV valve causing intermittant p0420 (catalyst efficiency below threshold)

The car is a 2002 Honda CRV with the 2.4 VTEC engine. Had it about two years, and I've done a fair amount of maintenance on it at this point. It's got a nagging, intermittent p0420 code. And ...
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1answer
1k views

My Toyota Corolla 2009 Le 1.8l fuel consumption too high

I run my car in normal use in highway and no traffic I spend $20 full tank 90 miles I replace my tires,spark plugs Oem ,Transmission fluid with filter,Engine oil with filter,Thermostat,antifreeze,Air ...
4
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2answers
821 views

Do oxygen sensors degrade over time or just break?

I have a BMW E46 M3 with 100k miles that's smelling rich when cold and seems to be getting worse mileage than it used to. It has passed the UK MOT emissions check recently, the plugs seem fine and I'...
1
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1answer
139 views

2001 VW Beetle 02 sensor car will not go over 65mph

I have a 2001 VW Beetle 2.0 engine with 171,000 miles on it. I have a check engine light on saying that bank 1 lean. It has been like this for years and I have had no problem with it. Yesterday I ...
1
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1answer
1k views

Short term fuel trim shows -9% (Rich)

Honda Civic 2007 90km odometer Problem- Fuel consumption I have scanned my car and it shows STFT -9% along with below parameters. Coolant temp -> 64 LTFT -> -7.03 Oxygen sensor voltage -> .55v EGR ...
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0answers
16 views

MAF sensor problem?

i have a 2012 vauxhall Zafira 1.7cdti ecoflex motor which has low mpg, i have tested for obd2 codes but there are none,live tests show MAF sensor readings fluctuating from 7.9 to 15.11 g/S on tick ...
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0answers
253 views

OBDLink Settings for Fuel Economy

Specs: App: OBDLink v5.4.1.1072 (iOS) Adaptor: OBDLink MX+ (bluetooth) Vehicle: 1999 Ford F250 7.3 turbo diesel (Aug 98 Production) Have been working with this Scantool for a couple weeks now, by ...
2
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1answer
85 views

Wheel covers for '95 Honda Civic EG with drum brakes

I have a 1995 Honda Civic hatchback with drum brakes. I am thinking of adding wheel covers (also called moon disks). Would this affect the drum brakes the same way it can sometimes affect disk ...
7
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1answer
51k views

What does a healthy spark plug look like?

The spark plug pictured here: Has some black carbon on the underside of the ground electrode and has black carbon on the "base" area below the centre electrode (not pictured). Is this normal and ...
1
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1answer
228 views

Land Rover Freelander 2 - Bad MPG

2007 Freelander 2 Was having what I consider bad MPG for a diesel, averaging around 23-24mpg Initially thought it needs a service, so lots of money later for a full service which would have ...
1
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1answer
124 views

Which value should takes to show Gauge value, Fuel pressure or Intake Manifold Pressure?

Currently, I'm working on an app which should show Gauge value (inHg) of the vehicle using OBD reader. Which values should I use to show the Gauge? Is there any formula?
17
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13answers
259k views

What does Honda's 'Econ' button do? Does it truly improve fuel efficiency?

I recently bought a Honda Civic that had this in the car: I have no idea what it does, and how it's supposed to help. Even Honda's website is ambiguous, just using a lot of fuzzy words to describe ...
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2answers
96 views

Do RPMs directly relate to fuel consumed?

I have heard that revolutions per second effect has mileage negatively, but I haven’t heard by how much. Is the relationship linear-ish (like with a little wiggle room for error) Or is the ...
0
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1answer
44 views

Load in higher gear vs fuel consumption

I saw a video explaining that put the car in higher gear where possible to avoid high revs thus maximising mileage, this lead a thought in my mind about what happens if the revs are low and gear is ...
1
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0answers
224 views

Truck burning through a lot of gas

Vehicle Information: 2006 Ford F150 4WD with the 5.4L Problem: On the way to work I noticed that the truck was "burning" a lot of gas. As I drove, (at a normal speed - 60 mph) I noticed that the ...
2
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5answers
2k views

Is Petrol usage Proportional to Gas Pedal position

I was wondering about this the other day. Is the petrol usage in the car only influenced by the position of the gas pedal? So for example if I take my foot of the gas and coast for 30 seconds, would ...
0
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0answers
42 views

Can transmission replacement affect fuel economy?

I recently had the transmission replaced in my 2009 Dodge Grand Caravan. This is my third Dodge minivan, and all of them averaged around 17 mpg in mostly city driving. However, when I got this van ...
0
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1answer
570 views

Am having too much fuel consumption on my Toyota Carina e 1994 model. Please what is the causes?

Having high fuel consumption on my Toyota Carina e 1994 model. Please what may be the causes?
14
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6answers
8k views

What is most fuel efficient at 130km/h? [duplicate]

Suppose a very hot summer day, driving on a long straight highway at 130 km/h. What is most fuel efficient solution : Driving with AC on and closed windows? Driving with AC off and four full opened ...
13
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2answers
33k views

How does ambient temperature affect engine efficiency and fuel consumption?

I remember from my physics class that the ideal-gas Carnot engine is more efficient if the temperature difference between the heat source and the thermostat ("heat recipient") is larger (http://...
9
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8answers
18k views

Fuel efficiency and Shifting/RPM

I was reading a thread in a car forum where someone wrote: The lower the RPM, the less fuel you use, the less strain you put on everything.. Another person then replied, stating: Not true. If ...
0
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1answer
36 views

Mitsubishi Pajero IO fuel

Which is the best fuel to use for Mitsubishi Pajero IO with the below specification: MODEL: GF-H66W MRXC ENGINE: 4G93 Unleaded 95 ,Unleaded 98 or anything else?
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0answers
35 views

fuel consumption and high ravs

I changed the sub assembly for my toyota altezza but now its consuming too much fuel and now the rav count will at 2000rpm at low speeds 20-60km/h, it had an engine check light for knock sensor and ...
9
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3answers
12k views

How much fuel does it take to start an engine?

I appreciate this is a question that can't be answered in facts and figures, so I'm after a general idea. I drive a 1986 Supra, which has a modest 2.8-litre engine. I often shut the engine off while ...
2
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3answers
430 views

Does a black car have worse fuel consumption?

As we all know, in hot climates part of the engine's output goes to power the AC compressor. Now, in such a climate, if your car is painted black, it should absorb more sunlight, and therefore, ...
9
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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 ...
21
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4answers
6k views

Does flooring the throttle while traveling at lower speeds increase fuel consumption?

I've noticed that in a manual transmission vehicle when going uphill I have two options: Downshift and press the gas more Stay in the same gear and press the gas more I haven't measured it but ...
0
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0answers
33 views

Seeking information on the accuracy of average Fuel Consumption shown in Instrument Console?

If the speed shown in a motorcycle's instrument cluster is off by let's say ~5 km/h relative to the actual speed, can we say that the average fuel consumption it shows is also prone to show wrong ...
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2answers
1k views

Calculating fuel flow rate through obd || sensor not supporting 015E and 0110 commands

I have been working on a project where i want to calulate fuel flow rate using data from the obd2 sensor. The car on which i was testing didn't support the pid 015E which is for fuel flow rate. Then i ...
5
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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 ...
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1answer
71 views

How many L/km does removing a spare tire save? [closed]

My grandparents in Toronto, Canada merely drive in the GTA, and don't need their spare tire in their car's trunk, as they don't know how to replace a tire and would merely call roadside assistance if ...
1
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1answer
58 views

oil light flash while pressing gas

I have Hyundai i30 2008, i have changed crankshaft sensor 1 week ago. two days ago i start hearing some noise from motor while in idle and also while moving. Today the check engine light turned on and ...
4
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1answer
533 views

Driving down hill in gear without throttle

I have read in an article that when the car is in gear instead of being in neutral while driving downhill, the pistons in the engine are being "rotated" by the rotational speed of the wheels. When ...
1
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4answers
434 views

Can spark plug wires affect fuel consumption

I am experiencing a drastic drop in mileage so far everything seems fine with the car so I cannot find the reason for now, but recently I replaced the spark plug wires I think it's unlikely that they ...
0
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2answers
197 views

Motorcycle - 2009 Yamaha Vstar 950 tourer - fuel overconsumption

Let me clarify first, I am no mechanic and this is my first owned bike (newbie). I bought my bike (Yamaha VStar 950 tourer, 2009) last year, it was pre-owned. I noticed that whether I drive in cold or ...
0
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0answers
86 views

How to calculate accurate fuel consumption for Diesel engine by using OBD data? [duplicate]

Can you recommend formula for calculating fuel consumption using OBD data for diesel engine? I find a article(http://www.windmill.co.uk/obdii.pdf) about fuel calculation using vehicle speed and MAF(...
7
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1answer
888 views

Volvo 2.0D engine “self-oscillates” after changing timing belt and adjusting fuel-injectors

I recently had the timing belt and water pump changed on my Volvo s40 (2006 2.0D diesel). The mechanic also cleaned and adjusted the injectors. After the service I noticed that att some rpms the ...
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2answers
1k views

Should diesels in general be run at higher rpm than gasoline cars?

I have always had gasoline cars, for which it appears (based on advice from other motorists and from fuel consumption meter), that it is advisable in general to run them between 1500-2000rpm. Going ...
0
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1answer
45 views

Civic Bad Mileage

I have honda civic 98 with D16Y4 engine and auto transmission.I'm getting low mileage 9-10km/L without a.c, driving with light foot with rpm between 2k-3k. I avoid long idling, drive within city ...
2
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3answers
87 views

Will a carbureted engine have different fuel consumption rates based on external load, with the same RPM?

I have a small Briggs and Stratton Model 19 engine, net power of 10.0 HP. If I ran the engine at full throttle without any external load connected to the output shaft, would it consume the same amount ...
2
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2answers
701 views

KIA Sedona 2003 Diesel Intercooler Turbo Low Fuel Mileage

I have a 2003 a Kia Sedona turbo diesel 2.9L, with intercooler. I am getting 5 km per liter of diesel consumed. I also have to do oil change and ATF replacement. I got the car 3 weeks ago. What are ...
2
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3answers
6k views

Realistc V8 fuel consumption and values displayed on vehicle instruments

My 2017 Grand Cherokee with the 5.7 "Hemi" V8 shows me instantaneous as well as average fuel consumption in a dashboard display. I am recording distance driven between refuelings and quantity pumped, ...
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0answers
71 views

LTFT zero on mazda cx7 2008 + high fuel consumption

I have this Mazda CX7 2008 2.3L turbo, and am experiencing the following: LTFT is zero, no matter what conditions I drive the car on. Gas consumption is high: ~22L/100km (10.6 MPG) DTC P2006: Intake ...
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2answers
35 views

Eco OBD2 Range Rover Sport Battery Issue?

I installed an Eco OBD2 and within 24 hours had a battery warning light showing and as the car is over 4 years old assumed that the battery was coming to the end of its life. I removed the Eco OBD2 ...
5
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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. ...
5
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3answers
1k views

Is manual start/stop good on older cars?

I have an old car (but with electronic injection) that predates by far start/stop systems which are used nowadays to save fuel (turning off the engine brings savings after 3-5 seconds, see Calculating ...
16
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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-...
5
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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 ...
0
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2answers
2k views

Relationship between torque, power, specific fuel consumption, and AFR

How does Torque, power, and specific fuel consumption change with AFR? And why is it so? I found graphs relating these in books as well as websites but I couldn't find any good explanations.I have ...

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