Unleaded Fuel – Raw Figures
Explanation of the Fuel Consumption Figures
These are the raw fuel consumption figures from when my Triumph Spitfire 1500 ran on unleaded fuel – after a new cylinder head was fitted. These figures were used to create the graph of unleaded fuel consumption.
The consumption figures are in miles per litre (mpl) as this is the easiest values to record in the UK now fuel is sold in litres. But for those who prefer miles per gallon (mpg) figures, a UK gallon is approx 4.5 litres. So:
9 mpl = 40.5 mpg
8 mpl = 36 mpg
7 mpl = 31.5 mpg
6 mpl = 27 mpg
Table of Figures
Date | Litres | Miles | Actual Values | Rolling Average |
---|---|---|---|---|
19 Apr 1999 | 16.89 | 144 | 8.53 | 8.53 |
20 Apr 1999 | 18.54 | 153 | 8.25 | 8.38 |
23 Apr 1999 | 19.97 | 154 | 7.71 | 8.14 |
05 May 1999 | 20.60 | 99 | 4.81 | 7.24 |
10 May 1999 | 22.07 | 181 | 8.20 | 7.45 |
23 May 1999 | 20.37 | 192 | 9.43 | 7.67 |
30 May 1999 | 12.81 | 91 | 7.10 | 7.48 |
12 Jun 1999 | 25.95 | 163 | 6.28 | 7.13 |
12 Jun 1999 | 19.60 | 173 | 8.83 | 7.94 |
14 Jun 1999 | 15.66 | 112 | 7.15 | 7.74 |
18 Jun 1999 | 18.08 | 143 | 7.91 | 7.40 |
19 Jun 1999 | 13.35 | 73 | 5.47 | 7.17 |
30 Jun 1999 | 20.86 | 186 | 8.92 | 7.85 |
18 Jul 1999 | 20.29 | 178 | 8.77 | 8.02 |
29 Jul 1999 | 19.18 | 150 | 7.82 | 7.84 |
02 Aug 1999 | 20.36 | 163 | 8.01 | 7.96 |
19 Aug 1999 | 21.61 | 179 | 8.28 | 8.03 |
31 Aug 1999 | 21.32 | 173 | 8.11 | 8.32 |
04 Sep 1999 | 22.52 | 195 | 8.66 | 8.29 |
11 Sep 1999 | 15.86 | 159 | 10.03 | 8.55 |
04 Oct 1999 | 19.78 | 130 | 6.57 | 8.27 |
09 Oct 1999 | 8.04 | 61 | 7.59 | 8.20 |
17 Oct 1999 | 22.08 | 187 | 8.47 | 8.29 |
07 Nov 1999 | 13.73 | 118 | 8.59 | 8.24 |
20 Nov 1999 | 21.20 | 190 | 8.96 | 8.39 |
28 Jan 2000 | 16.70 | 106 | 6.35 | 7.80 |
29 Jan 2000 | 17.59 | 153 | 8.70 | 8.20 |
11 Feb 2000 | 15.70 | 108 | 6.88 | 8.06 |
13 Feb 2000 | 16.19 | 154 | 9.51 | 8.20 |
26 Feb 2000 | 19.66 | 160 | 8.14 | 8.14 |
20 Mar 2000 | 15.00 | 129 | 8.60 | 8.03 |
20 Mar 2000 | 8.95 | 87 | 9.72 | 8.30 |
25 Mar 2000 | 17.71 | 160 | 9.03 | 8.58 |
11 Apr 2000 | 20.21 | 152 | 7.52 | 8.38 |
12 Apr 2000 | 13.77 | 115 | 8.35 | 8.58 |
12 Apr 2000 | 10.07 | 92 | 9.14 | 8.49 |
22 Apr 2000 | 18.36 | 174 | 9.48 | 8.64 |
24 Apr 2000 | 12.68 | 114 | 8.99 | 8.76 |
29 Apr 2000 | 20.63 | 171 | 8.29 | 8.70 |
29 Apr 2000 | 13.13 | 129 | 9.82 | 8.75 |
05 May 2000 | 17.45 | 168 | 9.63 | 9.08 |
07 May 2000 | 15.61 | 145 | 9.29 | 9.21 |
20 May 2000 | 18.32 | 140 | 7.64 | 8.86 |
21 May 2000 | 18.34 | 175 | 9.54 | 8.97 |
03 Jun 2000 | 20.36 | 163 | 8.01 | 8.91 |
09 Jun 2000 | 15.41 | 141 | 9.15 | 8.83 |
11 Jun 2000 | 14.65 | 123 | 8.40 | 8.64 |
15 Jun 2000 | 23.44 | 185 | 7.89 | 8.39 |
17 Jun 2000 | 20.49 | 171 | 8.35 | 8.50 |
18 Jun 2000 | 12.27 | 112 | 9.13 | 8.39 |
01 Jul 2000 | 16.58 | 112 | 6.76 | 8.21 |
22 Jul 2000 | 16.75 | 141 | 8.42 | 8.10 |
05 Aug 2000 | 15.65 | 118 | 7.54 | 7.98 |
12 Aug 2000 | 12.12 | 111 | 9.16 | 8.15 |
14 Aug 2000 | 15.86 | 137 | 8.64 | 8.19 |
11 Sep 2000 | 22.71 | 179 | 7.88 | 8.01 |
23 Sep 2000 | 18.12 | 142 | 7.84 | 8.18 |
24 Sep 2000 | 11.04 | 94 | 8.51 | 8.18 |
15 Oct 2000 | 17.77 | 99 | 5.57 | 7.81 |
05 Nov 2000 | 12.28 | 124 | 10.10 | 7.93 |
05 Nov 2000 | 9.15 | 63 | 6.89 | 7.70 |
11 Nov 2000 | 13.60 | 123 | 9.04 | 7.87 |
18 Nov 2000 | 16.18 | 130 | 8.03 | 7.91 |
13 Jan 2001 | 20.24 | 140 | 6.92 | 7.61 |
03 Feb 2001 | 20.45 | 141 | 6.89 | 7.85 |
03 Mar 2001 | 16.86 | 128 | 7.59 | 7.51 |
31 Mar 2001 | 21.35 | 171 | 8.01 | 7.66 |
01 Apr 2001 | 18.58 | 175 | 9.42 | 7.79 |
12 May 2001 | 12.31 | 78 | 6.34 | 7.59 |
29 May 2001 | 25.26 | 189 | 7.48 | 7.68 |
30 Jun 2001 | 10.30 | 75 | 7.28 | 7.80 |
14 Jul 2001 | 20.49 | 163 | 7.96 | 7.86 |
22 Jul 2001 | 17.32 | 163 | 9.41 | 8.09 |
16 Aug 2001 | 15.80 | 127 | 8.04 | 7.83 |
20 Aug 2001 | 18.96 | 163 | 8.60 | 8.14 |
22 Aug 2001 | 13.32 | 110 | 8.26 | 8.33 |
01 Sep 2001 | 15.55 | 138 | 8.87 | 8.52 |
17 Sep 2001 | 21.31 | 172 | 8.07 | 8.54 |
22 Sep 2001 | 16.53 | 148 | 8.95 | 8.46 |
13 Oct 2001 | 21.24 | 149 | 7.02 | 8.23 |
04 Nov 2001 | 19.58 | 173 | 8.84 | 8.28 |
Significant events during this period:
- 9 July 1999 – Full service + carbs cleaned out.
- 17 October 1999 – Multispark fitted. (see Note 1 below)
- 8 February 2000 – Kenlowe fan fitted. (see Note 2 below)
- 17 April 2000 – Service + leaky exhaust manifold fitted.
- 9 February 2001 – Full service.
- 14 October 2001 – Service.
Note 1
The Multispark is a unit placed in line with the lead to the distributor cap which delivers many sparks instead of one big one to each of the cylinders. Although as you can see there seems to be little or no impact on the fuel consumption, the engine was immediately a lot smoother and appeared to have more power so I perservered with it.
The pre-Multispark average consumption was 7.86 miles per litre and the average after was 8.25 miles per litre.
Note 2
The Kenlowe fan is an electric fan which replaces the previous mechanically driven fan. I was not expecting there to be much effect on fuel consumption, but there seems to be a small boost to the rolling average shortly afterwards.
I’d always recommend fitting a Kenlowe fan as the car was a lot quieter afterwards. Also there were no more tense moments sitting in heavy traffic on a hot day watching the temperature gauge rise. You can see a picture of the Kenlowe fan at the bottom of the Car History page.
