Effect of Gasoline Fuel Additives on Combustion and Engine Performance

H
RR,
 J
/CAD
Ignition Timing, CAD BTDC
CI-Additional Base
CI-Additional 1X

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6.3 Engine Testing 
153 
Figures 6.22 – 6.30 display the emissions analysis results. CI-A exhibited 
similar characteristics in the engine to those seen the in the combustion vessel. For 1X 
concentration, an improved oxidation was seen through reduced CO output and 
increased CO
2
, while at 10X treat rate, the fuel possessed characteristics closer to base 
gasoline. Reduced CO output could be explained through reduced flame quenching 
near cylinder walls which would increase CO
2 
and also likely the NO
x
emissions. 
However, it is again unclear as to why at 10X concentration the benefits could not be 
seen. It has been suggested by Linteris et al. [257] that for metallic antiknock additives
Figure 6.22: CO emissions CI-A 
Figure 6.23: CO emissions CI-I 
1.5
1.7
1.9
2.1
2.3
2.5
2.7
2.9
3.1
3.3
3.5
20
25
30
35
40
45
50
55
60
65
70
CO
 Co
ncent
ra
tio
n, 
%
Ignition Timing, CAD BTDC
CI-A Base
CI-A 1X
CI-A 10X
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
25
35
45
55
65
75
CO
 Co
ncent
ra
tio
n, 
%
Ignition Timing, CAD BTDC
CI-I Base
CI-I 1X
CI-I 10X

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6.3 Engine Testing 
154