20-03-2022, 04:22 PM
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.
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.