What will happen if you use regular unleaded gas in a 1999 Land Rover Discovery?

Answer 1

It could cause major damage to the engine or cause the engine to run poorly. However I took the chance and drove my 1997 L. R. Discovery for the past 100,000 miles and five years using regular unleaded fuel. The L. R. has run smoothly and has passed all smog test. It has had great power and no mechanical problems related to the 87 octane fuel. Premium fuel cost about $.30 more a gallon and I've averaged about 13 miles per gallon. .30 X 100,000 = 30,000 /13 = $2307.69 savings. The gas mileage might have been slightly better using premium knocking down the savings a little but I figure very little so my savings of more than $2000 have been worth it from my point of view. I purchased the vehicle for $7000 five years ago and it's worth less than a grand now so my depreciated cost per year has been about $1200. That's great for a classy Land Rover Discovery that still looks great and has been a wonderful transportation and a real workhorse for towing a car-hauling trailer (for small cars like Hondas, VWs Toyotas etc.) and doing my work as a mechanic.