How critical is it to use Premium gas in my Disco? Gas prices are obviously a concern right now, and I just wonder how much difference it really makes. Thoughts?



2000 Discovery II
110,000 Miles

 

If you think evey Disco owner runs premium, you'ld be wrong. But premium does get better mpg over time, and reduces a variety of engine problems. It will do best on premium. It will run on regular. Repair costs over time could be higher.

 

I run premium and it gets way better mpg! lol

 

Octane rating has no affect on fuel consumption. The quick and easy explanation is that the higher the octane, the slower the burn. Land Rover engineered and programmed their vehicles to use a slower burning fuel. Their timing is set up for the burn rate of the higher octanes. When you use a lower octane, you get engine knock/pinging. Also called pre-detonation. Not a good thing. The knock sensors then try to adjust the fuel trim and timing advance to compensate, but they are still under the impression that you are running a high octane fuel, and the compensations will only appear to work, but in the meantime you will slowly have issues surface that may or may not send the engine to an early grave. No one has ever done a true comparison to see what happens. So everything you hear is speculation. But in my case, the manufacturer says to use 90+ octane, so I do.

 

I would say we actually don't have premium fuel anymore, as the added octane is obtained by ethanol in some cases, and performnce suffers. Some of the oil suppliers near me now offer non-ethanol gasoline, and it is very popular with the outboard motor boat crowd (that be the red necks that need a 250 hp bass boat to chase down a fat lazy large mouth, who must be stone deaf if he can't hear that thing coming). So the premium we had in the 60's is nothing like we have today. Of course it had lead as well.

 

There is definitely a difference between premium leaded(or low-lead) fuel and premium unleaded in performance.

 

If your engine has a distributor, you can get by on regular. If it doesn't, follow the manual (high octane).

Easy-peasy lemon squeezy.

 

I don't know anyone that's put regular gas for any length of time. I have only used premium in mine. In theory, using regular will cause the gas to combust before it's supposed to, and will cause premature wear of the pistons, the rings, the valves, and may cause the pushrods to bend or the springs to break.

 

Every one so far has given the technical reason for using the proper grade of fuel.
Now here is the dollars and cents reason, from 20 gal it will cost you $5 more to fill the gas tank, that is when the low fuel light comes on, it is a 25 gal tank, low fuel light comes on with approx 5 gal left.
So, drink one less Starbucks coffee.
Bring your lunch to work one more day a week instead of going out for lunch.

And bottom line reason for using premium fuel, Land Rover says it is REQUIRED.

 

That is only if you adjust the timing advance to compensate for the different fuel...just so the OP knows.