I never use anything other than 87, runs fine. Been daily driving 3 discos (wife, daughter, me) since 2014.

 

I've done plenty of long hauls in TX with 87 6.5hr each way for example trips. For example 93 octane in my area was 3.29 (before the covid19 stuff) and 87 octane was 2.49. I filled up with 87 octane, and drove up to Austin/Marble falls/Lakeway 75-80MPH all the way there HVAC on full blast and just cruising along. I got 11.5 MPG on the way up there. On the way back I filled up with 93 octane since it was 15 cents more.... (I was bingo fuel so I got a full tank of 93 octane). I did the same route, same speed, same vehicle load, and HVAC on full blast and cruising along as usual. I got 12.5MPG on the way back, but I also had a decent tailwind on the way back.

In all my years of owning LR's I have yet to do a single repair that revolves around what octane fuel was used! I've replaced water pumps, power steering pumps, spark plugs, spark plug wires, 1 coil, fan clutches, fan blades, and coolant hoses. I also always monitor my engine temps, and the claims that a LR V8 running 87 octane will run hotter = false from all my driving and monitoring temps.

People also say owning a LR is easily 2-3k per year in maintenance cost if not more. I dunno if I've just owned nearly 20 flawless LR's or I just maintain them excellent, but once I buy a used LR and go over it from head to toe, and fix the issues it had when I initially bought it I DO NOT have to touch them for a very very very very long time. I've had my Kalahari 6 years and I've put nearly 40K on it. The only thing that popped up in 2 years ago was a clogged heater core and that cost me 6.00 in new heater core hose. The 99 D2 is the same way, all the stuff I've done to it were all modifications or upgrades. All my LR's have been extremely reliable, and comparable with the other 4x4's I've owned like Jeeps or Hummer H3's as far as yearly maintenance.

So getting back to the 87 vs 93 = use whatever you can get your hands on. If I lived in the mountains I'd get the highest octane I could due to those famous 7 mile mountain passes that some people seem to have issues with.... Haha couldn't help myself!!!

 

i run Premium in all my Rovers. it's cheap peace of mind. well, cheap here in the Midwest. Premium is currently around $2.09 and before the COVID shut down was still under $3.00/gallon.

the biggest difference i've seen in fuel is Premium with Ethanol vs Premium with no Ethanol.

every one of the Rovers that i have put Ethanol-free Premium in has run smoother, had more power and gotten better mileage.

unfortunately, i can only get the Ethanol-free Premium out of state.

Edit: grammar

 

Yeah ethanol free is very hard to find in TX (or all the gas stations I normally use from Beaumont to central TX).

 

disco mike would give you a ear full if he saw this

 

Remember to pay attention to the OP's location. Different countries use different methods for calculating octane ratings, so the first step would be to work out what "premium" is in NZ and what rating that would be at the pump in the US. (I grew up in NZ so I'm somewhat familiar with the systems there, although I haven't lived there in 25 years.)
I have run into performance issues when I ran regular grade fuel in my D2, but I don't think any damage resulted. The truck just started to run rough at idle and had less power at takeoff. If you're doing highway miles then it's less likely to be a problem.
But then you also have to remember that NZ doesn't have highways like the US has highways. There are a few places that are about equivalent, road-wise, but a lot of the country is far more single-carriageway road and a lot more twisty. So the importance of performance issues are likely going to be a function of the type of driving that the OP is generally doing.

 

We used to be on Discoweb at the same time back in the day. Hell LR themselves knew people drove em like old ladies! #1 thing we'd do was take a LR V8 vehicle for a test drive to diagnose it. Leave it in first gear, and floor it. If you looked behind you and saw a cloud of black smoke once it bounced off the rev limiter = it would go back and have LR Fuel Treatment added to the list of To Do's for that vehicle pretty much no questions asked. No way he could argue about that!

Now on anything 87-95 LR V8 with a distributor = 93 or that engine would ping up a hill or when passing someone. Chevron used to be the best back in the day. If you used Diamond Shamrock, or say a no name gas station it would still ping as their 93 wasn't really 93. Once LR went to GEMS/Bosch engine management and the distributor days were over knock sensors became standard and the ECU could adjust on the fly vs before.

I'm here to just offer real life advice/tips. Having 5 LR's with 3 D2's being setup nearly identical with nearly identical temps/MPG is kinda all the proof I need. If I just had one and couldn't actually compare stuff = I wouldn't comment on it. When I did the Dorman 620-112 fan blade/Hayden 2991 fan clutch I compared it side by side a good condition 99-02 LR setup. Only difference I saw/recorded was the Dorman Fan Blade/Hayden fan clutch was a little louder. Then I started recommending it. I would never give advice by just the seat of my pants on anything LR wise. Besides my main job LR's are my life. Ask anyone that knows me lol.

Heck just this weekend I went on a wild adventure with my Irish buddy in Spring, TX. He bought another 500.00 White D1 that had been sitting. It would not turn over to being immobilized. I drove out to Spring, TX Friday evening. We then hauled butt to San Antonio to grab his 98 D1. We loaded it up, and got caught in a really nasty storm cell. It was so bad we ended up passing 2 dedicated/marked Storm Chasing rigs with all kinds of electronic recording data/cameras/weather monitoring equipment. We finally got out in front of the storm and it was smooth sailing after that. We got back into Spring, TX around 2:30am. The next morning we unloaded it into his garage (small feat in itself). Returned the truck and trailer, and then I started to run down the list of things to check on why it wouldn't run. I hooked up my Lynx and it immediately told me what I was already suspecting P0335 No signal from the Crank Position sensor. I climbed under the D1 and I saw the problem in 5sec. The CPS plug was on the CPS, but it was not actually plugged in!!!!!!!!!! I told my friend & he said NO F'ing WAY..... Crawled out from under it, it fired right up like it had just been driven (had been sitting for 1.5 years). Now my friend can fix up 2 of his D1's with this 500.00 one (which could now run/drive perfectly fine) but he bought it specifically to part out. Just like the last one he bought which sat also for nearly 1.5 years out under a tree which also ended up being from a CPS harness that was shorted in like 3 places with a CPS that was just dangling off the engine.

I'm all about the adventure, the fun of diagnosing some else's vehicle they gave up on, and bringing it back from the grave, sharing my knowledge with 87-04 LR's to help people out, and I also really like to improve on some of the LR flaws with either new compatible better parts, or making a fix/mod myself. I walked away from LR's for about 5 years and tried Jeeps. I walked away not impressed at all. Sure you can make a Jeep Wrangler awesome off road after you replace just about every part on it, but then you can't really comfortably drive it on the road to the off road park vs a LR which you can modify to do both very well. I'm not into crawling up a 10-15ft solid rock wall. If I was I'd learn how to rock climb lol. I'm all about off roading like the Camel Trophy/Expedition Style and then driving your vehicle to and from the event. When I gave up on Jeep's and the new wave of Jeep owners I went back to LR's and I'm so happy I did. I've had nothing but great experiences with LR's for nearly 23 years, and I enjoy people with the same passion.

I've been to Mexico a few times, and I can only imagine some other remote places in the world but octane ratings are the least of your worries. When that team took the white D2's around the world I watched that show and they were worried about not finding 93 octane fuel. Their ride along mechanics were more worried about the quality of the fuel aka more water than fuel, or debris getting into the fuel system, octane was not on their minds. 93 is great like I said, but it will not die from 87. I have never heard a single one of my GEMS/Bosch LR V8's ever idle or sound weird with using lower fuel. The only thing that is going to notice anything = Engine Management System.

 

Just for the record when I tell people looking to buy a D2 that they should anticiapte $2000 a year in maintenance, I always specify that is if you take your truck to a shop, not just doing your own work and have lots of your own parts from doner vehicles.

I agree on budget gas, I notice less power on takeoff and rougher idle... Same with 87 octane. Though I've never tried that on a long trip... Or much at all for that matter.

Non Ethanol premium runs even better but I have no close access to that at reasonable prices. When I go to the rural areas of the state they have it and I fill up with it when I can.

 

We have a VP Racing fuel station in Beaumont with stuff like 107 octane fuel, but it's weird how you have to buy it. It's not like a normal gas station. They might sell 93 octane without ethanol, but I've even noticed a high amount of ethanol in diesel around here. My 2019 Mercedes Sprinter (new work van) says no more than 5% ethanol fuel recommended by the fuel filler neck. I've had it 2 weeks and all the diesel pumps say "this diesel fuel contains up to 20% ethanol". Up north near Lufkin, TX I saw a few independent stations selling non ethanol fuel, but sadly they've all closed up.

Yeah the yearly cost = some people talk about shops or parts. I had a friend try to take their 94 D1 D90 to a local LR dealership and if you can believe this they honestly had no clue what it was, then they told em all they could basically do was an oil change, tire rotation, and maybe an alignment.... They said any other work they'd have to order the parts, and just go from there. My friend was out the door pretty much after they had no clue what a 94 D90 was! He went to an independent shop and they had his D90 out the next day with a full brake job, all fluids swapped out, a tune up, and an alignment. I think he paid around 1500.00 for all that work. His D90 gets used, then it sits for several years, then it gets used, so his maintenance is due his D90 sitting more vs being used.

Only time I ever notice a loss of HP upon take off = in the summer months when the Hayden 2991 is locked and I'm basically an airplane engine until I get it up to around 2400-2600RPM when the Hayden 2991 finally disengages. Not to mention the air going into the intake is much warmer vs the cooler fall/winter months. The only difference in all my D2's which have the same mechanical upgrades/mods is that the 4.6L has more pep, but that is due to it being a 4.6L vs a 4.0L in the other two.

People are always shocked my 02 Kalahari with 237+ on it. You never feel it vibrate, it is extremely smooth, and with the magnaflow exhaust if there was any misfires or rough idle you would hear it no question. The only time the exhaust note changes is whenever the AC engages/disengages and the idle goes up/down accordingly.

The 03 I've got to install a PS pump into right now idles nice and sounds great, but OMG give it any throttle and the entire D2 shakes. It feels like the engine is totally out of balance. I've yet to really look into it, but I'm hoping it's just a bad harmonic balancer, or engine/trans mounts. It just turned 113K but it feels honestly like 500k + lol.

Heck the D1 I just got running for the first time in 1.5 years this weekend is running rough, but it also has god only knows how old of fuel in it. Idles great, but when you rev it up you can tell that fuel is awful.

I've been thinking about it, and thinking about it really really hard. My wife wants the LR3 gone, and I "could" sell it, and put the money into a 4.8L LS swap for my 04 D2 and let her drive it. However besides the roof paint that is just now starting to show signs of fading in a few spots. The 04 is completely flawless inside/out and every single thing works. I would hate to see it start falling apart from the wife n kids beating it up so nah I haven't pulled the trigger. If however I get one of my personal LR V8's to explode I would certainly go the 4.8L LS swap and keep it no question. Then goat ****/85/87 octane fuel for the rest of it's life for certain!

When I was younger I was all about having a brand new vehicle, but now nah no thanks. To many idiot driving aids that drive me nuts being a good driver, and they aren't designed at all to be worked on yourself.

I did see something funny a while back. I got an 04 D2 to work on and they wanted new wires, coils, and plugs. When I removed the plugs I was amazed to find the spark plug insulators stained a crimson red. I had never seen that before on a spark plug. I've seen plenty of fouled, or discolored plugs from coolant, lean/rich conditions, but never the insulator stained red! When I did a bit of digging around I found the owner had been using octane boosters and 87 octane fuel. Whatever that octane booster had in it apparently stained the insulators on all 8 plugs crimson red. If I remember correctly his octane booster of choice was made by STP lol.

RRC/D1/D2's are not 1/4 speed demons. I just leave a light at a normal pace and eventually get up to speed and stay there. Then if I get into steep hills I drop it into 3rd and leave it there until I can use OD again. I plan on a trip to the PNW one day taking one of my LR's on an epic cross country trip hitting up places I've dreamed of going in a LR.

 

The prices are from the Chevron and Shell stations here in Monterey that I use every week. Both of them, as of today at least, matched the prices in the little table I made. The 87, 89, and 91 grades at both brand's stations in this area increase by .10. Your GasBuddy search isn't wrong either, but it's just from gas stations with dumpster gas. The 7-Eleven down the street is indeed $2.95 for 91.

To all others, I wrongfully assumed all stations' octane levels were bracketed by 10 cents. The vast majority of stations in CA are that way.

I guess the overall takeaway is this: Weigh the actual cost increase between one grade and another and weigh it against the offsetting costs that may result as a consequence of using poorer quality or lower octane go-go juice.