NIPPY PETROL TANK WEIGHT

[Dennis Nicholas]

Have now got my new alloy petrol tank from Compbrake Motorsport.
It now comes with a screw on type filler cap so don't need an A7 one.

Of interest to the racing Nippy bods may be the weight?  My old tank 16.75lbs and new tank 12.75lbs so around 4 lbs lighter.
Now that also means more mpg...so just how many miles must I motor to save on the cost of petrol to pay for the new tank   .

Dennis

[Colin Morgan]

Quite a long way...

Losing the 4lb saves a bit of fuel on acceleration. Say you accelerate to 30mph on average every mile - losing 4lb would save about 750 joules of fuel energy expended every mile, given the engine is about 30% efficient. A litre of petrol contains energy of about 10KWHrs so 36 million joules. Therefore, a litre of fuel might be saved every 48,000 miles. Given a litre costs 165p at the moment, a penny is saved every 290 miles. If you paid, for example, £200 for the tank, then the cost would be recovered in about 6 million miles.

[Dennis Nicholas]

Ah. so not in my lifetime   I needed the tank anyway.
I like your mathematical genius.  I love details and detailed analysis.

Dennis

[Bob Culver]

Hi Colin

Of more relevance is the difference between a full and say 1/4 full tank. The greatest improvemnt in performance of my Seven was acheived by leaving my comprehensive tool box at home. For the first time in 60 years I now always do so as I have no idea how to fix anything on the the inherited Jazz I now occasionally drive.

[andrew34ruby]

I certainly have noticed that the seven goes up hill better when SWMBO isn't with me. Do I really need the spare wheel, jack, wheelbrace, tins of spare fuel, oil, water??? Fire extinguisher, drink, food?

[JonE]

...or indeed, one must ask, SWMBO?