Premium Gas?

[JMan]

Just noticed that the Disco says it needs premium. Why? Is it a high compression engine? I know that after i put a blower on my toyota i had to run 91, but thats because the engine would detonate if i didnt, not to mention other fuel system upgrades. But why the disco?

[GentrysRover]

Good day,

always run 93 or higher some sunoco have 94 It is needed if you dont will gum up valves and ruin injectors.. I have a 95 and ran 87 for a while and cause a lot of backfires and i had to clean it out with good injector cleaner ..I get 13 on high way as good as it gets Try running amsoil oil too will see a difference and runs better hope thiss helps

Eric

[parthog]

I have run premium most of the truck's life, it is apparently what the engine management is tuned for.

With lower octane, the engine will lower performance. It will also get worse mileage. I have run mid-grade with a measurable drop in MPG from my normal 18.5-20.5 to just under 17, so I feel that it is significant enough in the timing advance etc. to affect mileage. With the price of fuel these days premium is only 10% higher than regular, a smaller percent spread than 5years ago so I just stick with premium. It's possible that part of the premium fuel decision was based on marketing: the fuel mileage on the window sticker, or maybe by emissions based on the engine's burning premium cleaner, don't know.

One difference between premium and regular in most gasolines is the detergents and additive packages: A good premium will likely keep your injectors etc. cleaner than a regular fuel. I run RedLine fuel conditioner periodically to keep them clean, and always run it when I have lower-grade fuel, have so far dodged the dirty valve and injector bullet.

- Jeff

[Brutus]

If you do not run premium fuel you will end up needing a valve job because of carbon build-up on the exhaust valves. That is an expensive repair. Also remember to get on it every once in a while to clean the combustion chamber a little.

[JMan]

Originally Posted by parthog

I have run premium most of the truck's life, it is apparently what the engine management is tuned for.

With lower octane, the engine will lower performance. It will also get worse mileage. I have run mid-grade with a measurable drop in MPG from my normal 18.5-20.5 to just under 17, so I feel that it is significant enough in the timing advance etc. to affect mileage. With the price of fuel these days premium is only 10% higher than regular, a smaller percent spread than 5years ago so I just stick with premium. It's possible that part of the premium fuel decision was based on marketing: the fuel mileage on the window sticker, or maybe by emissions based on the engine's burning premium cleaner, don't know.

One difference between premium and regular in most gasolines is the detergents and additive packages: A good premium will likely keep your injectors etc. cleaner than a regular fuel. I run RedLine fuel conditioner periodically to keep them clean, and always run it when I have lower-grade fuel, have so far dodged the dirty valve and injector bullet.

- Jeff

how the hell are you getting 20 mpg? are you sure your dividing correctly? I get 10 in city and 14 on hwy.

[JMan]

Originally Posted by GentrysRover

Good day,

always run 93 or higher some sunoco have 94 It is needed if you dont will gum up valves and ruin injectors.. I have a 95 and ran 87 for a while and cause a lot of backfires and i had to clean it out with good injector cleaner ..I get 13 on high way as good as it gets Try running amsoil oil too will see a difference and runs better hope thiss helps

Eric

wow, yo can find 94 up there in vermont? my supercharged tacoma would love it. dam california, 91 the highest ive seen here.

[LANDY96]

Man... if the best some of you all are getting is 10-14 mpg, there is something seriously wrong with either your foot, or your engine. For those of you with that kind of mileage, check your pcv valves, and hoses to the valve-cover. If those are dirty clean them, and make sure there is air flow through them. Put premium fuel and injector cleaner through it and drive it a long distance. I have a 96 disco, and usually around town, I average about 15 mpg, and can get up to 19.5 on the highway,(going 65). I have not had gone on a long trip in a while, I plan to go on a trip next month. I made a few air intake modifications. I intend to drive it for @ 400 miles non-stop on the highway, and I will post my Average mpg.

[parthog]

Synth fluids, some snake oil, tires at 32psi, and cruise set at 75 (80 on the speedo, GPS says 75). Oh, and Amoco/BP premium.

[JMan]

Originally Posted by LANDY96

Man... if the best some of you all are getting is 10-14 mpg, there is something seriously wrong with either your foot, or your engine. For those of you with that kind of mileage, check your pcv valves, and hoses to the valve-cover. If those are dirty clean them, and make sure there is air flow through them. Put premium fuel and injector cleaner through it and drive it a long distance. I have a 96 disco, and usually around town, I average about 15 mpg, and can get up to 19.5 on the highway,(going 65). I have not had gone on a long trip in a while, I plan to go on a trip next month. I made a few air intake modifications. I intend to drive it for @ 400 miles non-stop on the highway, and I will post my Average mpg.

all right, im heading to big bear for some snowboarding on thursday, so ill be as conservative as i can to see how many mpg i get on the trip as a whole. ill let you know. And yes, i switched to mobile 1 on everything, tires at correct pressure, new tune up, no roof rack resistance either. Clean hoses, valves, etc... weeeeelllll seeee. thx.

[texasrover]

I still can not get over 19 MPG. You must have a defective Disco engine. You should check to see if there is any leaks. If dont have leaks, you should take it into the dealer, they will fix that for you.

I get around 13 mpg Highway. I run Amsoil, K&N air filter, proper tire pressure, new plugs and wires and Prem. fuel (93). To give you some idea I can go around 260-275 on a tank of gas before I hit fumes.

Keep your Rover, you have a rare one!!!

[Mr Tj]

Are we back to the discussion from the Range Rover boards of UK vs US gallons? Sounds like it.

[JMan]

well i got back from the mountains and overall mpg is 16mpg. I was being nice to it, not flooring it, never went over 75, premium gas, wind behind me, 1 hr before dusk... you catch my drift....

[02disco2]

Man..

Someone better pass what they are smoking. Seriously.

I can MAYBE get 310miles out of a full tank. That is a combination of city/highway driving. Ususally average 11-13MPG. I have hit 15 once on a trek to my lake home.

BTW, I've had the same mileage since it was new. It hasn't fluctuated at all, ever.

[pboerger]

On a trip from Dallas to NYC and back this past December with the car fully loaded and with no special tuning I got about 15 MPG on the interstate using regular fuel. Otherwise I am lucky to get about 11-12 MPG around town.

I just replaced the plugs (Bosch platinum) and ignition wires (silicone Bosch from Autozone 29.99) after the return trip and while the truck runs better the MPG seems about the same.

BTW, I don't recall any documentation from Land Rover about the Disco's requiring premium fuel.

[GentrysRover]

They recommend it manual too use only premiun fuel.. Thats what I use I would look in your manual again