Here is a Lambda chart...

Lambda E85 AFR Gas AFR
0.500 4.880 7.350
0.510 4.978 7.497
0.520 5.075 7.644
0.530 5.173 7.791
0.540 5.270 7.938
0.550 5.368 8.085
0.560 5.466 8.232
0.570 5.563 8.379
0.580 5.661 8.526
0.590 5.758 8.673
0.600 5.856 8.820
0.610 5.954 8.967
0.620 6.051 9.114
0.630 6.149 9.261
0.640 6.246 9.408
0.650 6.344 9.555
0.660 6.442 9.702
0.670 6.539 9.849
0.680 6.637 9.996
0.690 6.734 10.143
0.700 6.832 10.290
0.710 6.930 10.437
0.720 7.027 10.584
0.730 7.125 10.731
0.740 7.222 10.878
0.750 7.320 11.025
0.760 7.418 11.172
0.770 7.515 11.319
0.780 7.613 11.466
0.790 7.710 11.613
0.800 7.808 11.760
0.810 7.906 11.907
0.820 8.003 12.054
0.830 8.101 12.201
0.840 8.198 12.348
0.850 8.296 12.495
0.860 8.394 12.642
0.870 8.491 12.789
0.880 8.589 12.936
0.890 8.686 13.083
0.900 8.784 13.230
0.910 8.882 13.377
0.920 8.979 13.524
0.930 9.077 13.671
0.940 9.174 13.818
0.950 9.272 13.965
0.960 9.370 14.112
0.970 9.467 14.259
0.980 9.565 14.406
0.990 9.662 14.553
1.000 9.760 14.700
1.010 9.858 14.847
1.020 9.955 14.994
1.030 10.053 15.141
1.040 10.150 15.288
1.050 10.248 15.435
1.060 10.346 15.582
1.070 10.443 15.729
1.080 10.541 15.876
1.090 10.638 16.023
1.100 10.736 16.170
1.110 10.834 16.317
1.120 10.931 16.464
1.130 11.029 16.611
1.140 11.126 16.758
1.150 11.224 16.905
1.160 11.322 17.052
1.170 11.419 17.199
1.180 11.517 17.346
1.190 11.614 17.493
1.200 11.712 17.640
1.210 11.810 17.787
1.220 11.907 17.934
1.230 12.005 18.081
1.240 12.102 18.228
1.250 12.200 18.375
1.260 12.298 18.522
1.270 12.395 18.669
1.280 12.493 18.816
1.290 12.590 18.963
1.300 12.688 19.110
1.310 12.786 19.257
1.320 12.883 19.404
1.330 12.981 19.551
1.340 13.078 19.698
1.350 13.176 19.845
1.360 13.274 19.992
1.370 13.371 20.139
1.380 13.469 20.286
1.390 13.566 20.433
1.400 13.664 20.580
1.410 13.762 20.727
1.420 13.859 20.874
1.430 13.957 21.021
1.440 14.054 21.168
1.450 14.152 21.315
1.460 14.250 21.462
1.470 14.347 21.609
1.480 14.445 21.756
1.490 14.542 21.903
1.500 14.640 22.050

Around .80-.85ish seems to be what you want to shoot for (So far my car has liked .82), so around 12 on AFR.