I know this has been discussed before...but here is an interesting article:

http://auto.howstuffworks.com/premiu...y-vehicles.htm

 

Which has absolutely nothing to do with Rovers.
If you want to loose a couple MPG, low end power and torque and carbon up your engine then burn regular and see what pops up down the road in the form of carboned up valve issues.

 

This is a direct quote from that article, I copied it and pasted...

The first thing you should do is check your owner's manual

In other words USE THE GAS THAT THE MANUFACTURE SAYS TO USE!!
LR says right in the owners manual that fuel with a minimum pump octane rating of 91 is REQUIRED.
it's not because of the compression ratio on a Rover engine, it is because of the fact that there is not EGR (exhaust gas recirculation) valve on a Rover V8.
The EGR does 2 things.
1-it recirculates the exhaust gases back into the combustion chambers to be burnt which helps reduce emissions.
2-it recirculates exhaust gases back into the combustion chambers to COOL them.
Rover V8's do not do this, premium gas burns cooler than regular gas, it also burns better (more complete) than regular gas.
So you get more bang for your buck.
Thats why you get better MPG when you use premium gas.
I use premium in everything, lawnmower, snowblower, chainsaw.
I dont use it in rental cars or my work van, they get the cheapest stuff I can find.

 

Funny you mentioned rental cars Spike, I used to design automated fuels systems for the government, and had to fill something up with E-85 before anyone knew what e-85 was. That little Maxima ran just fine on it....

To the OP --- Premium is required. (notice the period)

 

Every once in awhile I run E-85 in my van, the Volvo too, it makes a great fuel injector cleaner but thats about it.
It sucks as a motor fuel.

 

What about, Octane Boosters??

Cheap Gas with Octane Booster vs Premium Fuel

 

lol... How much is a good octane booster lately? $15? $20?...

 

Read the fine print on the octane booster, most only raise octane rating by .5, so your 87 octane would be roughly 87.5.
Next price the octane booster, $3-$5 per bottle, one bottle treats max 20 gallons of gas.
Our Disco's hold 25 gallons.
Now lets do some simple math-
$2.00 per gal of 87 octane.
$2.10 per gal of 89 octane.
$2.20 per gal of 93 octane.
This is called the "ten cent spread", this is common practice for all gas stations.
So, 20 gal of 87 octane is what? "Bueller? Bueller?" $40
20 gal of mid grade is $42
20 gal of premium is...wait for it...$44.
Now take your $20 tank of regular gas and add a $4 bottle of octane booster and what do you get?
Its not a trick question, I'm waiting...$44.
$44 for 20 gallons of 87.5 octane gas when the Discovery requires min 91 octane.
Now dilute that 20 gals with another 5 gals of 87 without octane booster and what do you get? 87.01 octane.
Are we clear? Everyone?
Octane boosters are a gimmick.

 

Isn't that answering a question with a question??

 

the combustion chambers in the rover v8 get hot. ever had to replace your headgaskets? but thats why it need the good stuff. the higher the octane the harder it is for the fuel to combust, 87 will burn sooner then 93, be that under high temperature or high compression. something thats designed for 87 wont nessacarily perform any better on 93, and could be worse. rovers were made to use premium, use it.