LWB Roadster with 1.8TC MPG?

[redmonty]

20 years ago when I last had my LWB Marlin Roadster 1.8TC on the road I didn't really bother too much about MPG... fast forward to 2024 I am now curious as to how many MPG my Marlin should be expected to return. Although my car has 1 3/4 SUs I have now found the original 1 1/2 SUs in a box. So there are 2 questions, for the 1 1/2 twin SUs does anyone have any MPG figures and just out of interest is there anyone out there running twin 1 3/4 SUs and has checked their MPG?

Although the engine is now running there is still quite a lot of work required to sort out brakes and clutch which are seized after being in storage for so long, so I won't be able to do my own check for some time (hopefully its just the hydraulics that need sorting out). So just out of interest does anyone have any figures on this? I know the much heavier marina 1.8 TC had very poor MPG of low 20s!

[martinclan56]

My Triumph based car, with twin 1 1/2 SU's used to do upper 30's with fairly spirited driving. I was 40 years younger then :-)
I would guess, if set up correctly, you should expect mid 30's. That B Series engine is a heavy old lump....

[redmonty]

My Triumph based car, with twin 1 1/2 SU's used to do upper 30's with fairly spirited driving. I was 40 years younger then :-)
I would guess, if set up correctly, you should expect mid 30's. That B Series engine is a heavy old lump....

Thanks Martin, if I could get those sorts of figures I would be a very happy bunny. Not knowing which engine, how many cylinders and whether you have overdrive or not, I have no way of knowing if this is comparable or achievable with a 1.8 B series engine. I have this feeling the figures for a 1.8 B series will be much lower than yours even with less spirited driving.

[Ye Ol Ripper]

I have a 1.8 TC SWB with marina box ( hence no overdrive). Approx 34 mpg travelling at 2-2.5k rpm . It is likely to be better mpg at 3-3.5k rpm though