M.P.G. in a Herald 13/60

[Jeffds1360]

What do you guys tend to average?

I've been fettling and tuning on the drive the last 6 months or so, now that I have had a couple of runs out I'm looking at my log book and working it out!

Started at 7MPG, mainly at tickover in July August! 7 gallon used

Improving to 10MPG with occasional spins round the block in November, but still sorting on drive, using 4 gallon. 

Then up to  12MPG in December January when I went out on trips of about 2 miles, using  another 4 gallon, with the odd session at tickover.

Up to 15MPG in February, When a few 5-6 mile trips, used another 4 gallon. 

Last fill indicates 23MPG now we're a bit off the leash and the car is all sorted.

is that the best I can expect? I'm just cruising about.....

[Paul H]

My Vitesse mk2 ranges from 22 to 29mpg though a 1500 mile Irish Trip over 2 weeks it averaged 29.5 mpg 

Paul 

[mishmosh]

I have a 1300 spit in my herald. So thirsty compared to a 13/60  

thrashing around country lanes 20 mpg. Motorway and a roads 35. Snowdonia trip. 28-30. 

[Chris A]

In my 13/60 I get in the lower end of the 30's.

[Jeffds1360]

Hmmmm. Quite a variation then. Actually,  mine is a MkIV spitfire engine too. 

Is there really that much difference between that and the original 13/60?

I only have the single 150CD carb. But a Toledo box with OD.

 

[Pete Lewis]

two big thing that affect MPG 

the heavy right foot 

and a duff reading oddometer 

Pete

[mishmosh]

If you are using a single carb you won’t really see the minor advantage of the spit engine. You should get low thirty’s. V

[Clive]

49 minutes ago, mishmosh said:

If you are using a single carb you won’t really see the minor advantage of the spit engine. You should get low thirty’s. V

Not so sure, especially on a 1300. JT did the swap on a 1500 spit (twin HS4 to single, and back, every race) and the twins made a few more ponies(less than 5 IIRC) and the single did a couple of MPG more. This is on a bog std, but VERY well built engine that he won an allcomers racing championship, beating alfas etc. He used te car as a daily on teh single carb to save fuel, and raced on the twins. Both set up on a rolling road so a proper comparison.

So it seems single or twin carbs make little difference. The higher CR and cam etc are probably the important factors.

 

As to MPG, check the dizzy i working correctly, especially the vac advance. And it is matched to the engine....

[Jeffds1360]

Thanks Clive, I've gone with the 45D as I knacked the 25s springs and cannot find replacements.

It is set up well.

I have new jet and needle plus the o rings so I will replace and set the carb up again after a bit more testing. Cheers.

[sulzerman]

I consistently get up to 45MPG on a run with my spitfire 1500  overdrive. 

[Mathew]

6 minutes ago, sulzerman said:

I consistently get up to 45MPG on a run with my spitfire 1500  overdrive. 

I was going to say my old 1500 spitfire would get average 45mpg and up to 50 with careful driving . I had a gpx motorbike that would get over 50mpg but drop down to 19mpg if i thrashed it. It hasn't got binding brakes?

[Jeffds1360]

Well I eventually got the jet, needle and new 'o' rings fitted and now the fuel gauge reading will not go down !!!!!.

Brilliant

It was just above half, I  have done about 50 miles and it is just below half.  What a difference an 'O' makes

Majic.

in fact, when I parked on the drive, sloping back a touch, the gauge went UP.