What's the deal with premium gas only? I have owned an 01', an 02', and an 03' discovery 2 and I ran regular unleaded in all 3 with no problems at all. These "premium' car brands like to make you feel like you're driving something special and should only run "premium" gas in them, because it's a "premium" engine....all it tells me is that your 70 year old engine design sucks so bad that you can't run regular old gas like every other car on the road. Multiple studies have shown that the mileage and performance increases are negligible and not worth the extra cost, so what gives? The only time I ran premium in my land rover was when I was getting lean running condition codes just to help prevent any pre-ignition, but once the vacuum leak was fixed and the air/fuel ratio was back to normal, I went right on back to regular ol' gasoline. Maybe there is a Rover tech out there that can confirm...is it just a status thing? Don't get me wrong, I love my land rovers and wont drive anything else; but this gas grade thing has gotten on my nerves. Discuss!

 

Running regular (assuming that means 87 octane) is known to increase carbon buildup in these engines, which can damage the valvetrain.

My understanding is the "premium" Land Rover recommends is actually mid-grade in the US, but the price difference is so minimal where I live there's no point in not putting 93 in it.

To paraphrase Toby Ziegler, don't tempt the wrath of the whatever from high atop the thing. The Rover V8 is enough of a hunk of junk without you throwing off-grade gasoline at it.

 

I’d say 87 octane is fine “if” you don’t drive it like Mrs. Daisy! You are NEVER going go get away from carbon build up with a Rover V8. I use 87 often and I drive my D1/D2’s pretty hard RPM wise. I also use seafoam in the tank at every oil change. I like 89 octane, but I use 87 when the price is just nuts!

The difference in 87/89/93 in TX used to be .10 to .15 per gallon difference. Sadly it’s more like .65 to 1.00 per gallon just for 89/93 octane depending on the gas station.

 

The other difference is the ECU is programmed for premium and you can't flash or change that. Thus when you do use lower octane, yes it will run, but using it's knock sensors it will detect the lower octane and "adjust" which is a feature designed so that if you are stuck in BFE Africa and you need fuel and the only available fuel is in a 2 liter coke bottle, it will work. The adjustment though is to retard your timing. So if you are ok running at less than optimum power and mileage then go for it. Just keep in mind that lower power and lower mileage make saving 20 cents a gallon pretty much a wash.

If you going to own one of these premium luxury SUV's you shouldn't just maintain it like its a chevy.

 

91 is what the the octane rating requirement in NA works out to. I find my Disco also prefers fuel with no Ethanol

 

I will poke the bear with a stick, typically in Washington state:

Truck = 24 gallons
Delta on gas price from lowest grade to highest grade approximately .30
24 x .30 = $7.20 extra per fill up with the highest grade
$7.20 x 52 weeks = $374.40 extra per year

The reason I post this is that yes, things add up but does that $7.20 a week really impact your budget. Considering we all spend a fair amount of money on our trucks, I have never fully understood the desire to find cheaper gas options. If that amount of money breaks the bank for you, why would you get a truck with crappy MPG.

Now, is premium really needed, my understanding is that the trucks are tuned for a range of grades that = premium. By not using this grade, you will get less performance and potentially lower MPGs. If the truck had a highly tuned engine, you would notice the difference. However, because our trucks are old and poorly tuned I doubt anyone could really feel the delta in performance unless your butt dyno is finely tuned.

So...does the lower grade fuel cause potential damage or negative long term effects on the truck, no clue on my side as I have never had a first hand account. I have only heard stories that start with "I had a buddie that" or "I knew a guy that said"

 

Or the other option you pay the extra $$, but are you truly getting 89/91/93??? Are you verifying the octane at every fill up??

I have towed a D2 with a D2, I do the carbon test on all my D2’s (leave in 1st gear until it hits the rev limiter) and hardly any black smoke comes out. I use 89/93 when I can, but most of the time it’s been 87 and I have zero issues. MPG is 10-12MPG on a lifted, larger tires (taking in account for that), HD bumpers, winch, roof rack, large aux lights, and a 4.0L

I wish it was only .30 more per gallon around here, but that is not the case. I’m not cheap when it comes to maintaining a LR, but over all the years I’ve owned LR’s I’ve only had a 94 RRC that ran awful on anything but Chevron 93 octane fuel. I don’t know how many times I’d fill up and be 5 miles down the road & you could hear it pinging from the “so called” 93 octane fuel. Which gets me back to my point are you really getting 89-93 octane fuel in the first place???

If I was rolling coal, barely getting 8MPG, and going thru engine overhauls like my kids go thru snacks then yep I’d only run 93 octane.

 

@Best4x4 I feel your pain 87 here is at 1.28 a liter about 5.06 a gallon, 91 is 1.52 6.08 a gallon so 20 bucks a tank more. But no ethanol in the 91 at Shell and the Disco is not a commuter vehicle so I just suck it up

 

I also find the non ethanol premium makes a big difference in how smooth the engine runs. Only one gas station in Seattle has that and it is $5.00/gallon there. Most rural areas have it, I guess for lawn mowers and such, at a more reasonable price, maybe .25 cents above ethanol premium. We are not lucky in the PNW in that all gas runs about $1.00/gallon over the national average. Premium here in town runs from 3.75 - 3.99... I just did a 700 mile trip to the Southern Oregon coast and found Chevron supreme in Salem for 2.99!! Generally 3.35 for Chevron supreme in Portland and on the coast. If I lived in BC i'd be tempted to drive to Bellingham for a fill up!

 

I feel like I should ban people that start gas or oil threads

I run 87 dosed with 2 drops of unicorn blood