introduction

Vehicle fuel economy refers to the ability of a vehicle to complete a certain mileage with the minimum fuel consumption under certain driving conditions. The evaluation indicators of vehicle fuel economy mainly include fuel consumption per 100 kilometers at constant speed and comprehensive vehicle fuel consumption, among which the comprehensive vehicle fuel consumption includes fuel consumption in urban working conditions and fuel consumption in suburban working conditions.

1. Automotive fuel economy simulation parameters

Total car mass m/kg	Coefficient of rolling resistance $f$	Air resistance coefficient $C_D$	Windward frontal area A/ $m_2$	Rolling radius r/m	Rotating mass conversion factor $d$	Transmission efficiency $η_t$	Gear ratio of final drive $i_0$	$i_g$ of each gear of the transmission $i_{g}$	Density of fuel oil $p$
2470	0.012	0.42	2.7	0.835	1.1	0.95	4.1	[4.016,2.318,1.401,1,0.778]	0.7

2. Universal characteristic curve of automobile engine

1. MATLAB program

be1=[222.8,220.4,232.4,228.5,227.8,232.6,248.5,245.9,272.4,329.7];%发动机燃油消耗率赋值
Ttq1=[399.8,354.1,318.5,278.1,236.2,203.6,185.3,157.2,117.2,80.8];%发动机转矩赋值
T1=80:320/9:400;%转换矩阵格式
Be1=interp1(Ttq1,be1,T1,'spline');%n=1400r/min时,采用一维三次样条插值处理
be2=[222.0,221.7,235.4,226.5,230.5,236.8,249.1,276.1,407.9,487.0];
Ttq2=[409.1,365.7,328.3,284.1,243.7,203.2,164.3,123.9,83.5,39.7];
T2=39:371/9:410;
Be2=interp1(Ttq2,be2,T2,'spline');
be3=[226.0,225.3,226.4,233.9,242.1,283.3,253.9,271.4,323.5,468.6];
Ttq3=[408.3,368.3,328.3,289.0,244.4,208.8,167.7,132.1,89.5,46.1];
T3=46:363/9:409;
Be3=interp1(Ttq3,be3,T3,'spline');
be4=[206.5,231.1,231.1,233.0,242.0,244.9,265.0,299.8,398.0,596.8];
Ttq4=[425.6,380.3,332.7,290.9,244.4,205.1,160.2,114.5,68.8,30.7];
T4=30:396/9:426;
Be4=interp1(Ttq4,be4,T4,'spline');
be5=[234.7,259.8,235.5,237.6,242.8,292.3,277.9,308.7,396.2,605.9];
Ttq5=[420.7,379.6,334.6,291.6,244.4,202.8,157.5,116.0,74.1,37.8];
T5=37:384/9:421;
Be5=interp1(Ttq5,be5,T5,'spline');
be6=[174.2,242.2,252.1,287.4,253.6,263.6,290.6,316.8,378.0,518.8];
Ttq6=[404.6,360.5,322.7,283.0,243.3,205.5,162.1,124.7,86.8,52.4];
T6=52:353/9:405;
Be6=interp1(Ttq6,be6,T6,'spline');
be7=[256.9,253.7,253.5,260.0,303.8,280.7,300.6,346.6,435.6,812.9];
Ttq7=[378.0,344.7,310.3,264.3,226.1,186.8,154.2,115.3,76.3,34.1];
T7=34:344/9:378;
Be7=interp1(Ttq7,be7,T7,'spline');
be8=[257.9,295.3,282.4,288.7,301.9,329.7,357.0,475.4,580.3,1080.1];
Ttq8=[315.6,275.5,242.5,210.3,178.5,145.6,118.6,72.6,52.8,22.4];
T8=22:294/9:316;
Be8=interp1(Ttq8,be8,T8,'spline');
Be=[Be1';Be2';Be3';Be4';Be5';Be6';Be7';Be8'];
n=[1400*ones(10,1);1600*ones(10,1);1800*ones(10,1);2000*ones(10,1);2200*ones(10,1);2400*ones(10,1);2600*ones(10,1);2800*ones(10,1)];
Teq=[T1';T2';T3';T4';T5';T6';T7';T8'];
x=[ones(80,1),n,Teq,n.^2,n.*Teq,Teq.^2];%多元线性回归设置
b=regress(Be,x);%多元线性回归函数
[n,Teq]=meshgrid(0:4800,0:600);%生成格点矩阵
be=b(1)+n.*b(2)++Teq*b(3)+n.^2*b(4)+n.*Teq*b(5)+Teq.^2*b(6);%计算燃油消耗率
Pe=Teq.*n/9550;%计算功率
[f,g]=contour(n,Pe,be);%绘制等高线图
clabel(f,g);%给等高线添加标签
xlabel('n/(r/min)');
ylabel('Pe/kW');
title('万有特性曲线图');
legend('燃油消耗率g/(kW*h)');

2. Running results

Universal characteristic curve of automobile engine

3. Forecasting the fuel consumption per 100 kilometers at constant speed

1. Fuel consumption per 100 kilometers at constant speed

1.1 MATLAB program

m=2470;%质量
R=0.358;%滚动半径
nt=0.95;%传动效率
CD=0.42;%空气阻力系数
A=2.7;%迎风面积
f=0.012;%滚动阻力系数
g=9.8;%重力加速度
dt=1.1;%旋转质量换算系数
p=0.7;%燃油的密度
u=input('请输入最高档车速（60~140）：');%输入车速
ne=[1400*ones(1,10),1600*ones(1,10),1800*ones(1,10),2000*ones(1,10),2200*ones(1,10),2400*ones(1,10),2600*ones(1,10),2800*ones(1,10)]';
%发动机转速赋值
Teq=[399.8,354.1,318.5,278.1,236.2,203.6,185.3,157.2,117.2,80.8,409.1,365.7,328.3,284.1,243.7,203.2,164.3,123.9,83.5,39.7,408.3,368.3,328.3,289,244.4,208.8,167.7,132.2,89.5,46.1,425.6,380.3,332.7,290.9,244.4,205.1,160.2,114.5,68.8,30.7,420.7,379.6,334.6,291.6,244.4,202.8,157.5,116,74.1,37.8,404.6,360.5 322.7,283,243.3,205.5,162.1,124.7,86.8,52.4,378,344.7,310.3,264.3,226.1,186.8,154.2,115.3,76.3,34.1,315.6,275.5,242.5,210.3,178.5,145.6,118.6,72.6,52.8,22.4]';
%发动机转矩赋值
be=[222.8,220.4,232.4,228.5,227.8,232.6,248.5,245.9,272.4,329.7,222,221.7,235.4,226.5,230.5,236.8,249.1,276.1,407.9,487,226,225.3,226.4,233.9,242.1,283.3,253.9,271.4,323.5,468.6,206.5,231.1,231.1,233,242,244.9,265,299.8,398,596.8,234.7,259.8,235.5,237.6,242.8,292.3,277.9,308.7,396.2,605.9,174.2,242.2,252.1,287.4,253.6,264.6,290.6,316.8,378,518.8,256.9,253.7,253.5,260,303.8,280.7,300.6,346.6,435.6,812.9,257.9,295.3,282.4,288.7,301.9,329.7,357,475.4,580.3,1080.1]';
%发动机燃油消耗率赋值
x=[ones(80,1),ne,Teq,ne.^2,ne.*Teq,Teq.^2,ne.^3,ne.^2.*Teq,ne.*Teq.^2,Teq.^3];%多元线性回归设置
b=regress(be,x);%多元线性回归函数
ne1=linspace(1400,4000,200);%定义转速范围
Teq1=linspace(0,600,200);%定义转矩范围
[X,Y]=meshgrid(ne1,Teq1);%生成二维网格矩阵
be1=b(1)*ones(200,200)+b(2)*X+b(3)*Y+b(4)*X.^2+b(5)*X.*Y+b(6)*Y.^2+b(7)*X.^3+b(8)*X.^2.*Y+b(9)*X.*Y.^2+b(10)*Y.^3;
%计算燃油消耗率
Pe1=Teq1.*ne1/9550;%计算功率
it=0.778*4.1;%计算最高档传动比
Pe=(m*g*f*u/3600+CD*A*u^3/76140)/nt;%计算匀速行驶所需功率
n=u*it/(0.377*R);%计算发动机转速
Be=interp2(Pe1,ne1,be1,Pe,n);%二维插值法得到燃油消耗率
Qs=Pe*Be/1.02/p/g/u;%计算百公里燃油消耗量
fprintf('最高档等速百公里燃油消耗量Qs = %.2f L/100km\n',Qs);%输出等速百公里燃油消耗量

1.2 Running results

Fuel consumption per 100 kilometers at constant speed

2. Constant speed 100 km fuel consumption curve

2.1 MATLAB program

u=60:10:140;
Qs=[13.90,9.97,7.69,7.06,7.94,9.82,11.78,12.29,9.17];
plot(u,Qs);
values=spcrv([[u(1) u u(end)];[Qs(1) Qs Qs(end)]],3);%曲线圆滑过渡设置
plot(values(1,:),values(2,:));
xlabel('车速/(km/h)');
ylabel('燃油消耗量/(L/100km)');

2.2 Running results

Constant speed 100 km fuel consumption curve

4. Using NEDC working conditions to predict the comprehensive fuel consumption of vehicles

1. Accelerate some MATLAB programs

function[Qa]=jiasu(a,u1,u2)
m=2470;%质量
R=0.358;%滚动半径
nt=0.95;%传动效率
CD=0.42;%空气阻力系数
A=2.7;%迎风面积
f=0.012;%滚动阻力系数
i0=4.1;%主减速器传动比
ig=[4.016,2.318,1.401,1,0.778];%各档位的变速器传动比
g=9.8;%重力加速度
p=0.7;%燃油的密度
%汽车的基本参数
ne=[1400*ones(1,10),1600*ones(1,10),1800*ones(1,10),2000*ones(1,10),2200*ones(1,10),2400*ones(1,10),2600*ones(1,10),2800*ones(1,10)]';
%发动机转速赋值
Teq=[399.8,354.1,318.5,278.1,236.2,203.6,185.3,157.2,117.2,80.8,409.1,365.7,328.3,284.1,243.7,203.2 164.3,123.9,83.5,39.7,408.3,368.3,328.3,289,244.4,208.8,167.7,132.2,89.5,46.1,425.6,380.3,332.7,290.9,244.4,205.1,160.2,114.5,68.8,30.7,420.7,379.6,334.6,291.6,244.4,202.8,157.5,116,74.1,37.8,404.6,360.5 322.7,283,243.3,205.5,162.1,124.7,86.8,52.4,378,344.7,310.3,264.3,226.1,186.8,154.2,115.3,76.3,34.1,315.6,275.5,242.5,210.3,178.5,145.6,118.6,72.6,52.8,22.4]';
%发动机转矩赋值
be=[222.8,220.4,232.4,228.5,227.8,232.6,248.5,245.9,272.4,329.7,222,221.7,235.4,226.5,230.5,236.8,249.1,276.1,407.9,487,226,225.3,226.4,233.9,242.1,283.3,253.9,271.4,323.5,468.6,206.5,231.1,231.1,233,242,244.9,265,299.8,398,596.8,234.7,259.8,235.5,237.6,242.8,292.3,277.9,308.7,396.2,605.9,174.2,242.2,252.1,287.4,253.6,264.6,290.6,316.8,378,518.8,256.9,253.7,253.5,260,303.8,280.7,300.6,346.6,435.6,812.9,257.9,295.3,282.4,288.7,301.9,329.7,357,475.4,580.3,1080.1]';
%发动机燃油消耗率赋值
X=[ones(80,1),ne,Teq,ne.^2,ne.*Teq,Teq.^2,ne.^3,ne.^2.*Teq,ne.*Teq.^2,Teq.^3];%多元线性回归设置
b=regress(be,X);%多元线性回归函数
ne1=linspace(0,4000,200);%定义转速范围
Teq1=linspace(0,600,200);%定义转矩范围
[X,Y]=meshgrid(ne1,Teq1);%生成二维网格矩阵
be1=b(1)*ones(200,200)+b(2)*X+b(3)*Y+b(4)*X.^2+b(5)*X.*Y+b(6)*Y.^2+b(7)*X.^3+b(8)*X.^2.*Y+b(9)*X.*Y.^2+b(10)*Y.^3;
%燃油消耗率
Pe1=Teq1.*ne1/9550;%计算功率
x=u2-u1+1;
Qt=zeros(x,1);%生成x*1维矩阵Qt
for i=1:x      %循环语句
    u=u1+i-1;   %计算速度
    if(u>=0&&u<=15)  
    it=ig(1)*i0;
    end 
%如果是一档车速范围计算一档传动系统传动比
    if(u>15&&u<=25)  
    it=ig(2)*i0;
    end   
%如果是二档车速范围计算二档传动系统传动比
    if(u>25&&u<=35)
    it=ig(3)*i0; 
    end 
%如果是三档车速范围计算三档传动系统传动比
    if(u>35&&u<=55) 
    it=ig(4)*i0; 
    end   
%如果是四档车速范围计算四档传动系统传动比
    if(u>55)         
    it=ig(5)*i0;
    end  
%如果是五档车速范围计算五档传动系统传动比
Pe=(m*g*f*u/3600+CD*A*u^3/76140+p*m*u*a/3600)/nt;%计算加速行驶所需功率
ne=u*it/(0.377*R);%计算发动机转速
b=interp2(Pe1,ne1,be1,Pe,ne);%二维插值法得到燃油消耗率
Qt(i)=Pe*b/367.1/p/g/1000;%计算加速工况百公里燃油消耗量
end
deltat=1/3.6/a;%计算每一段的加速时间
Qa=0;%将总燃油消耗量赋值为0
    for j=2:x-1
    Qa=Qa+Qt(j)*deltat;
    end 
Qa=Qa+(Qt(1)+Qt(x))/2*deltat;%计算总的燃油消耗量
end

2. Uniform velocity part MATLAB program

function[Q]=yunsu(u,t)
m=2470;%质量
R=0.358;%滚动半径
nt=0.95;%传动效率
CD=0.42;%空气阻力系数
A=2.7;%迎风面积
f=0.012;%滚动阻力系数
i0=4.1;%主减速器传动比
ig=[4.016,2.318,1.401,1,0.778];%各档位的变速器传动比
g=9.8;%重力加速度
p=0.7;%燃油的密度
%汽车的基本参数
ne=[1400*ones(1,10),1600*ones(1,10),1800*ones(1,10),2000*ones(1,10),2200*ones(1,10),2400*ones(1,10),2600*ones(1,10),2800*ones(1,10)]';
%发动机转速赋值
Teq=[399.8,354.1,318.5,278.1,236.2,203.6,185.3,157.2,117.2,80.8,409.1,365.7,328.3,284.1,243.7,203.2 164.3,123.9,83.5,39.7,408.3,368.3,328.3,289,244.4,208.8,167.7,132.2,89.5,46.1,425.6,380.3,332.7,290.9,244.4,205.1,160.2,114.5,68.8,30.7,420.7,379.6,334.6,291.6,244.4,202.8,157.5,116,74.1,37.8,404.6,360.5 322.7,283,243.3,205.5,162.1,124.7,86.8,52.4,378,344.7,310.3,264.3,226.1,186.8,154.2,115.3,76.3,34.1,315.6,275.5,242.5,210.3,178.5,145.6,118.6,72.6,52.8,22.4]';
%发动机转矩赋值
be=[222.8,220.4,232.4,228.5,227.8,232.6,248.5,245.9,272.4,329.7,222,221.7,235.4,226.5,230.5,236.8,249.1,276.1,407.9,487,226,225.3,226.4,233.9,242.1,283.3,253.9,271.4,323.5,468.6,206.5,231.1,231.1,233,242,244.9,265,299.8,398,596.8,234.7,259.8,235.5,237.6,242.8,292.3,277.9,308.7,396.2,605.9,174.2,242.2,252.1,287.4,253.6,264.6,290.6,316.8,378,518.8,256.9,253.7,253.5,260,303.8,280.7,300.6,346.6,435.6,812.9,257.9,295.3,282.4,288.7,301.9,329.7,357,475.4,580.3,1080.1]';
%发动机燃油消耗率赋值
X=[ones(80,1),ne,Teq,ne.^2,ne.*Teq,Teq.^2,ne.^3,ne.^2.*Teq,ne.*Teq.^2,Teq.^3];%多元线性回归设置
b=regress(be,X);%多元线性回归函数
ne1=linspace(100,4000,200);%定义转速范围
Teq1=linspace(0,600,200);%定义转矩范围
[X,Y]=meshgrid(ne1,Teq1);%生成二维网格矩阵
be1=b(1)*ones(200,200)+b(2)*X+b(3)*Y+b(4)*X.^2+b(5)*X.*Y+b(6)*Y.^2+b(7)*X.^3+b(8)*X.^2.*Y+b(9)*X.*Y.^2+b(10)*Y.^3;
%燃油消耗率
Pe1=Teq1.*ne1/9550;%计算功率
    if(u>=0&&u<=15)  
    it=ig(1)*i0;
    end 
%如果是一档车速范围计算一档传动系统传动比
    if(u>15&&u<=25)  
    it=ig(2)*i0;
    end   
%如果是二档车速范围计算二档传动系统传动比
    if(u>25&&u<=35)
    it=ig(3)*i0; 
    end 
%如果是三档车速范围计算三档传动系统传动比
    if(u>35&&u<=55) 
    it=ig(4)*i0; 
    end   
%如果是四档车速范围计算四档传动系统传动比
    if(u>55)         
    it=ig(5)*i0;
    end  
%如果是五档车速范围计算五档传动系统传动比
Pe=(m*g*f*u/3600+CD*A*u^3/76140)/nt;%计算匀速行驶所需功率
n=u*it/(0.377*R);%计算发动机转速
b=interp2(Pe1,ne1,be1,Pe,n);%二维插值法得到燃油消耗率
Qs=Pe*b/1.02/p/g/u;%计算百公里燃油消耗量
Ss=u*t/3600;%计算行驶距离
Q=Qs*Ss/100;%计算这段距离的燃油消耗量
end

3. Deceleration part of the MATLAB program

function[Qd]=jiansu(a,u3,u4)
Qi=1.5;%单位时间怠速燃油消耗量
t=(u3-u4)/3.6/a/3600;%计算减速时间
Qd=Qi*t;%减速工况百公里燃油消耗量
end

4. Idle part MATLAB program

function[Qid]=daisu(ts)
Qi=3;%怠速工况单位时间燃油消耗量
Qid=Qi*ts;%怠速停车燃油消耗量
end

5. NEDC part of MATLAB program

%计算城市部分等速行驶工况燃油消耗量和行驶路程
Qs1=yunsu(15,8)+yunsu(32,24)+yunsu(35,13)+yunsu(50,12); 
Ss1=(15*8+32*24+35*13+50*12)/3.6/1000;
%计算市郊部分等速行驶工况燃油消耗量和行驶路程
Qs2=yunsu(70,50)+yunsu(50,69)+yunsu(70,50)+yunsu(100,30)+yunsu(120,10);
Ss2=(70*50+50*69+70*50+100*30+120*10)/3.6/1000;
%计算城市部分加速行驶工况燃油消耗量和行驶路程
Qa1=jiasu(1.04,0,15)+jiasu(0.83,0,15)+jiasu(0.94,15,32)+jiasu(0.83,0,15)+jiasu(0.62,15,35)+jiasu(0.52,35,50);
Sa1=(15^2/1.04+15^2/0.83*2+(32^2-15^2)/0.94+(35^2-15^2)/0.62+(50^2-35^2)/0.52)/25.92/1000;
%计算市郊部分加速行驶工况燃油消耗量和行驶路程
Qa2=jiasu(0.83,0,15)+jiasu(0.62,15,35)+jiasu(0.52,35,50)+jiasu(0.43,50,70)+jiasu(0.43,50,70)+jiasu(0.27,70,100)+jiasu(0.28,100,120);
Sa2=(15^2/0.83+(35^2-15^2)/0.62+(50^2-35^2)/0.52+(70^2-50^2)/0.43*2+(100^2-70^2)/0.27+(120^2-100^2)/0.28)/25.92/1000;
%计算城市部分减速行驶工况燃油消耗量和行驶路程
Qd1=jiansu(0.69,15,10)+jiansu(0.92,10,0)+jiansu(0.75,32,10)+jiansu(0.92,10,0)+jiansu(0.52,50,35)+jiansu(0.86,35,10)+jiansu(0.92,10,0);
Sd1=((15^2-10^2)/0.69+10^2/0.92+(32^2-10^2)/0.75+10^2/0.92+(50^2-35^2)/0.52+(35^2-10^2)/0.86+(10^2)/0.92)/25.92/1000;
%计算市郊部分减速行驶工况燃油消耗量和行驶路程
Qd2=jiansu(0.69,70,50)+jiansu(0.69,120,80)+jiansu(1.04,80,50)+jiansu(1.39,50,0);
Sd2=((70^2-50^2)/0.69+(120^2-80^2)/0.69+(80^2-50^2)/1.04+50^2/1.39)/25.92/1000;
Qid1=daisu(60/3600);%怠速工况单位时间燃油消耗计算城市部分怠速工况燃油消耗量
Qid2=daisu(40/3600);%怠速工况单位时间燃油消耗计算市郊部分怠速工况燃油消耗量
S1=4*(Ss1+Sa1+Sd1);%市区部分行驶距离   4*:在市区的时间占大部分
Q1=4*(Qs1+Qa1+Qd1+Qid1)/S1*100;%市区部分平均燃油消耗量
S2=Ss2+Sa2+Sd2;%市郊部分行驶距离
Q2=(Qs2+Qa2+Qd2+Qid2)/S2*100;%市郊部分平均燃油消耗量
s=S1/(S1+S2);%计算市区行驶距离比例
Q=Q1*s+Q2*(1-s);%计算综合燃油消耗量
fprintf('汽车综合工况燃油消耗量：%.2f L/100km\n',Q);%输出汽车综合工况油耗
fprintf('汽车市区工况燃油消耗量：%.2f L/100km\n',Q1);%输出汽车市区工况油耗
fprintf('汽车市郊工况燃油消耗量：%.2f L/100km\n',Q2);%输出汽车市郊工况油耗

The simulation program is mainly divided into the main program part and the sub-function part. The main program part 'NEDC' is used to calculate the fuel consumption under the NEDC working condition. Four sub-function parts are called in the main program, and the four sub-function parts are respectively used to calculate the fuel consumption in the NEDC working condition. The fuel consumption of the 'acceleration' part, the fuel consumption of the 'constant speed' part, the fuel consumption of the 'deceleration' part and the fuel consumption of the 'idling' part.
In MATLAB, create 5 script files and save the programs of the above five parts respectively. The main program part can be named arbitrarily. Click the run button in the saved main program editor and the command window will output the simulation results.

6. Running results

Using NEDC Conditions to Predict Automobile Comprehensive Fuel Consumption

Summarize

It can be seen from the universal characteristic curve of the automobile engine that if the constant fuel consumption rate curve is larger in the direction of the abscissa, it indicates that the fuel economy of the engine is better when the engine speed changes greatly and the load changes less; If the constant fuel consumption rate curve is larger in the direction of the ordinate, it indicates that the fuel economy of the engine is better when the engine runs under the condition of a large load change and a small speed change.
The fuel consumption per 100 kilometers at a constant speed of a car is the best at a medium speed, and it will increase at low and high speeds. At low speed, the engine speed is small, the combustion of the engine is insufficient, and the fuel consumption increases; at high speed, air resistance needs to be overcome, and the air resistance is proportional to the square of the vehicle speed. The faster the vehicle speed, the greater the resistance, and the fuel consumption increases. big. Because the car often has various working conditions such as acceleration, constant speed, deceleration and idling during actual driving, the fuel consumption per 100 kilometers at a constant speed is often low, which is quite different from the actual fuel consumption per 100 kilometers.
NEDC is actually a test standard for the mileage of vehicles. Currently, there are three common test methods in the world, namely NEDC, WLTP, and EPA. The NEDC working condition is used to predict the comprehensive fuel consumption of the vehicle, which is relatively close to the actual fuel consumption per 100 kilometers of the vehicle.
Note : ** Because China's auto industry started relatively late, the standard formulation also follows the NEDC standard. It is worth mentioning that China has been working hard to establish its own driving cycle standards for many years. In recent years, China has launched the CLTC cycle, drawing on the test standards of developed countries such as Europe and the United States. The data collection is more subdivided. In addition to first- and second-tier cities such as municipalities and provincial capitals, it also has good coverage of third- and fourth-tier cities; the collection roads cover urban areas, suburbs, trunk roads, branch roads, expressways, secondary trunk roads, and expressways, etc., and the collection time covers spring and summer Working days, holidays, peak hours and flat peak hours in autumn and winter are more in line with the driving habits of Chinese users. The specific test items include urban working conditions, suburban working conditions and high-speed working conditions, and the cycle time is 1800 seconds.
Prior to this, my country's auto industry has always used the NEDC operating condition battery life standard. This set of standards only covers urban and suburban road conditions, and does not take into account high-speed road conditions and some detailed conditions such as congestion and acceleration. The time is short (1180s) and the mileage (10.93km) is small. It is difficult to measure the characteristic parameters under different conditions in detail. It is gradually replaced by CLTC. Compared with NEDC, its test road conditions are closer to the actual domestic road driving conditions.

Car Theoretical Fuel Economy Simulation - MATLAB