Really, What would Happen???

[jeffro0502]

I saw 100 octane advertised in Denver once....I could probably win a race with that stuff...

Highest we get here is 93 I think...thats what goes in, for some reason the last few tanks have been a little over 16.

 

[RovinAround]

As stated before... gas is cheaper than coffee... bottled water... beer... even orange juice...

This is true, but I'm sure the vast majority of us aren't buying 30 gallons of coffee or OJ a week....

 

[Slappy]

I saw 100 octane advertised in Denver once....I could probably win a race with that stuff...

Highest we get here is 93 I think...thats what goes in, for some reason the last few tanks have been a little over 16.

There's 100 octane at a 76 station in San Jose, CA also. We just used that in track cars, @5 bucks a gallon it's not going in my Rover.
I run 91.

Steve

 

[Tempest]

This is true, but I'm sure the vast majority of us aren't buying 30 gallons of coffee or OJ a week....

Actually, when I travel... I spend more $ in starbucks during the week than an entire tank of premium.

Gas in the USA is CHEAP...

 

[adriatic04]

if stations around me had 91, I would use that, but unfortunately it is 87, 89, 93.

regardless of what you put in it, its a pig, and never gets good MPG, if we can't afford the 2-3k a year in fuel, buy a golf cart

 

[ptschram]

Also there is a warning in the manual not to use fuel system cleaners as they can damage gaskets/seals... doesn't list any specifics really... does say gas with detergents is good.

LOL, this is curious. Look at your maintenance schedule and you will see that part of almost all services includes a portion of a Rover fuel system cleaner!

Been running cheap gas ever since I've owned a Rover. Don't have one with fewer than 150K miles. Oh NOES! Cheap gas is gonna kill my engines! I hope it's not too late to switch!

 

[Tempest]

I thought cheap gas was going to make the airbags inoperable???

p 121 of my manual: "Fuel system cleaning agents should be avoided, as many of these products can be harmful to gaskets and other materials used in the fuel system components".

Sounds like a bunch of bullshit since its in the maintenance schedule. Maybe the original purpose of it in there is to give LR additional ways out of not covering a warranty repair... lol...

On the same page: "The use of octane enhancers is not recommended, and may invalidate the vehicle warranty" I really wanted to use the 100 octane at the drag strip this weekend... trying to get sub 20's in the 1/4 mi.

LOL, this is curious. Look at your maintenance schedule and you will see that part of almost all services includes a portion of a Rover fuel system cleaner!

Been running cheap gas ever since I've owned a Rover. Don't have one with fewer than 150K miles. Oh NOES! Cheap gas is gonna kill my engines! I hope it's not too late to switch!

 

[Nanbakat]

I own an '03 Disco with the 4.6L engine. In my case, I started off using regular low-octane gas but switched to higher octane gas after I started having problems with the EVAP system. The higher octane gas costs more at the pump (about 8 bucks more per fill-up) but I get much better gas mileage with the higher octane gas. I haven't done the actual math, but the higher price coupled with better fuel economy means that premium fuel comes out to about the same price compared to low-octane fuel. However, the car drives better and there is better acceleration with the high octane fuel....both positives. Also, premium fuel is cleaner and has less sulfur than low-octane fuel (at least in Mexico) so I think that your engine will thank you in the long run.

In summary...there is no "real" difference in cost and there are only positives to using premium fuel.

 

[MUSKYMAN]

in summary sulfur is a lubricant added to fuel and is good for the valves but bad for the environment.

premium fuel is NOT cleaner in many respects, the octane level is raised by adding burn inhibitors to slow the flame front across the combustion chamber and prevent pre-ignition.

so thanks for the post but you just added more misinformation to the thread:applause:

 

[briancbev]

I have found that my 2001 Disco does get better gas milage with premium, if, and only if, the gas is the kind that is NOT mixed with up to 10% ethanol - as is seemingly required here in Houston, Texas.

In the event that you can only get gas that contains up to 10% ethanol, then use the cheap stuff because your gas milage will suck eitherway!!!!

 

[keepitwildtv]

I found something on the internet the other day that called them the "Rover Low Compression V8." Is that what's in the Disco or is that something else?

Really, when it somes down to it, if the compression is high enough it will start the gas burning. Regular, or "the cheap stuff" wants to burn faster and quicker under pressure than the 90, 91, 92, 93 or 100. The taller grade is not more powerful, but more controled...needing the spark to ignite. If the compression is not there to set it off then what's the deal?

I know the smaller Japanese engines have problems with the regular, but there wound tighter than some Disco owners. These V8's may be more on the lower side...I don't know. I'll give the 91 a shot and see. BTW, the compression on my old Nissan was 9.5:1 and it knocked bad on regular.

Also, how is a question about hearing a knock "false economy?" Please read the goddamn post before responding.

 

[R_Lefebvre]

First of all, my point about false economy was that using regular gas is not saving you any money over using premium, because it ends up using more gas and in fact costing you more. Why are you running regular gas in a truck that the OEM states should use premium? They didn't do that just to make Rover owners spend more money. It's because they must have a shitty combustion chamber design that is prone to detonation even with low compression.

Second, octane rating has NOTHING to do with burn speed. It is only a measure of the fuel's resistance to autoignite.

Third, all "Spark Ignition" (aka Otto cycle, aka gas engines) need the spark to ignite. They will never ignite purely from compression. That is the Diesel cycle. Sometimes they can preignite from localized hot spots (usually carbon deposits) but that's a different matter.

The smaller Japanese engines do not have problems with regular. Up to 10:1 compression running on regular gas is completely normal these days. If your old Nissan needed premium, it was either because it was a high performance engine designed for it, or there was something wrong with it.

 

[MUSKYMAN]

I found something on the internet the other day that called them the "Rover Low Compression V8." Is that what's in the Disco or is that something else?



Also, how is a question about hearing a knock "false economy?" Please read the goddamn post before responding.

there is a high and low compression version of the rover engines, you can see the compression by looking at the driver side of the block between the head and the exhaust manifold.

most are the 9.3-1 compression that is the high compression version.

R Lefebvre's post on false economy was right on the button. The reason the comment about hearing knock is bull shit is because in gems and newer rovers you will never hear the knock the system is designed to detect knock and retard the spark to prevent engine damage. this happens so fast you will never actually hear the knock the truck will just drive sluggish and get worse mileage. it will get enough worse mileage that the money you save at the pump will get eaten up in less miles per tankfull.

get it now?

Second, octane rating has NOTHING to do with burn speed. It is only a measure of the fuel's resistance to autoignite.

.

this is incorrect, flame speed propagation is a direct result of motor octane rating of the fuel being burned.

in a nut shell fuels that ignite easily also burn fast, fuels that are hard to ignite burn slower.

being a diesel head this stuff is just a given

 

[R_Lefebvre]

this is incorrect, flame speed propagation is a direct result of motor octane rating.

in a nut shell fuels that ignite easily also burn fast, fuels that are hard to ignite burn slower.

Well, this is contrary to my texts. Maybe the scientific understanding has changed since they were written in the 90's. Entirely possible.

They state that during a normal combusion event (ie: not a preignition event) flame speed propagation is little affected by octane.

 

[MUSKYMAN]

Well, this is contrary to my texts. Maybe the scientific understanding has changed since they were written in the 90's. Entirely possible.

They state that during a normal combusion event (ie: not a preignition event) flame speed propagation is little affected by octane.

I THINK the reason why this is now the common belief is that just about everything has a well designed combustion chamber.

Going back decades to simple designs with no specific quench area and before engine builders thought about spark plug placement all this was much more important. and any short commings in design had to be overcome with higher octane slower burning fuels.

 

[keepitwildtv]

I started using 91 in my '96 today. I never really thought it was a balance between price & performance, but if it would make the engine knock. It was loud on the Nissan I had, but never noticed it in the Rover.

Now I know why. If I can get more MPG and keep the engine from always having to adapt to the 87 then I'm all for it. More MPG means the thing is running better.

I'll see if it works.

 

[dutchman]

Just do a searc on google and there is so much to read about the types and differences in fuel and what octane has to do with the equation it will keep you amused.

 

[Tempest]

I used the internet... I found this great HH2O kit... hardwired it right up... takes 50% premium and 50% water... only downside is that its incompatable with the airbags. The solution I have for that is a pillow duck taped on the steeling wheel... I prefer goose down.