Fuel Mileage - how far on a tank

[billwill]

Playing with the bleed valve in the bottom of the float chamber can make drastic results in mileage. The accelerator pump moves a lot of fuel every time you move your foot, extra fuel your engine does not need. Saying a steady foot makes for better mileage is spot on. Try enlarging the bleed hole until it starts diminishing your performance. It will help increase your mileage.

Rob Walker
26-4889

On a Delorto, the throw of the accellerator pump is adjustable by two nuts locked together on a screwed rod at the engine side of the carbs.

You have to take them off to get at the adjustment, so it is tedious.

Too little throw & you won't be able to pump the throttle to prime the engine to start it.

[alexblack13]

It is just possible to adjust them with the carbs on but you need three very small hands!! I have been thinking of replacing the little two nut (lock nut!) setup with a three mm nylock. Anyone done this? It should then be possible with a little ratchet spanner (Got one) to set the throw to suit. My carbs are still very rich on the acc' pump and it is causing a slight rich cut / flat spot. Livable with but could be better.

Alex....

[richardcox_lotus]

Well.....got back earlier. 246 miles in total, mainly M-Way & Dual Carriageway. Arrived having travelled at a sedate pace (60-70) & then 40 mins traffic jam. Went home & 20 mins traffic jam before plain sailing. So....topped up shortly after leaving the circuit ( I reckon I used between 1/3 & 1/2 a tank on the morning journey), putting in another 16.5 litres. That brimmed it again - & I still have over half a tank left.

So I reckon I would have made it without a fill-up, which is comforting to know the range would probably be 260-270 miles. Also, I concur with the steady throttle position style of driving - minimal inputs as mentioned earlier.

Good to see so many Lotus F1s. Even the 43 ! (Lotus BRM). Such a shame it was sans engine....

If I get time I'll put some pics up.

Regards
Richard

[scott]

I put newly rebuilt dellortos on my 1970 s-4se using a 150 hp twincam with a ZF 5 speed and got 6 mpg I've gradually tuned from there and got 36 mpg when I thought I had it about right. Drove 90 miles today mostly on curvy secondary roads and returned 39 mpg. One plug looked a little lean so I've adjusted that barrel slightly. Think I've got it pretty close now Scott

[Frank Howard]

My Stromberg Elan regularly returns 29 miles per U.S. gallon around town. For highway driving, it gets 35. Last weekend, I completed an 800 mile trip in my 5-speed big valve Stromberg Europa Special. Averaging 70 m.p.h., I got 37 m.p.g. Apparently, the extra gear is worth no more than 2 m.p.g. so one of the benefits of performing a 5-speed conversion on the Elan probably deserves reconsideration.

[StoatWithToast]

I was checking my mpg a lot towards the end of last summer before the car was put away for all the work. I was getting around 32-38mpg depending on conditions and as I knew the engine was being rebuilt I was not very, erm, mechanically sympathetic, shall we say (e.g. only below 5,000rpm when waiting at junctions).

[Mazzini]

I really would like to hear what owners of Elans with a five speed box and EFI are getting to the gallon.

[john.p.clegg]

Mazzini

You will shortly,I've just altered my cruising ratio to 16.5:1 and am going to finish this tank full on my trip over to Sheffield tomorrow,going to VOSA as they want to double-check my chassis number...

P.S. I wasn't really doing 95mph on my way to Newark Autojumble Sunday morning...

Shortly

John

[john.p.clegg]

Not best pleased,just filled the tank and am getting 38.7mpg,was hoping for the upper 40's but there is still room to maneuver yet...

John

[gordont]

it all sounds way too accurate to me... I get about a weeks driving to a tank...

[Mazzini]

Hi Gordon,

I guess petrol isn't as heavily taxed in Oz as it is in the UK?

All the best,

Louis

[gordont]

AUD$1.50 a litre, issue is more a fuel gauge that is dodgy to say the least!

[Mazzini]

I'm paying approximately AUD $ 2.10, I think most of that goes to HMG in tax.

[Spyder fan]

I did 262 miles yesterday just for a service and MOT, topped the 11 gallon tank right up the night before and still have half a tank left. I get way over 40mpg on a run, even when I am baiting the repmobiles who think I'm driving an old and slow sportscar. Perhaps I'm cheating using a zetec with fuel injection?

My old twincam did over 40mpg so long as you didn't go over 70mph on a run.

regards

[elansprint71]

Fit a diesel.