I've got a real high mileage Disco I, from 1994. I have always read that you MUST USE PREMIUM gas. For the most part, like 99% of the time I do, but I wonder....I have been to remote small towns in need of gas and the only thing available was unleaded regular. I have reluctantly put this in. Seemed to run OK. Whats the real story here? Surely at 194,000 miles the compression on the engine has dropped enough to not always need Premium? This is a USA truck with the 3.8 litre V8, fuel injected.

 

Basically the highest octane that we have readily available is 91-93. When the trucks came out the lowest Europe had was I beilive 90 or 91 or something like that. So the engines were built to low on the cheapest gas over there to be the most economical. Running regular will just make your engine run like crap. So to answer the question, if it was an emergency yes you can run regular but try as much as you can not to or is said scenario were to happen you could prepare for it and buy an add in octane booster from your local auto parts store or sometimes even gas stations