and leprechauns ride unicorns to potluck dinners with santa

this entire thread is filled with misinformation.

not every car gets better miles from premium. some make more power, some make more mpg. it's all about the motor design and the tune of the computer.

octane rating is a rating of the amount of energy required to achieve combustion. provided it's not knocking- the higher the octane rating, the lower the power output.

when you use a lower octane fuel, the ECU or DME or whatever you would like to call it reads inputs from the knock sensors and adjusts fuel injector pulse width to use more or less fuel as the situation requires.

using lower octane fuel at worst will cause more fuel to be put into the cylinders causing an enriched situation AND THE ENGINE TO RUN COOLER

this is where things get interesting however; in order to keep NOx emissions down, the computer (REGARDLESS OF OCTANE) throws extra fuel it KNOWS it can't burn into the engine JUST TO COOL IT. this has been going on for a long time and it's one of the auto industries dirty secrets.

this is disgustingly worse at WOT and this applies to any EFI vehicle.

so why preheat the induction charge (TB heater) just to have to add too much fuel to cool the cylinders?

1. no egr
2. not enough swirl


the EGR recycles exhaust gases for the purpose (originally) of reclaiming some of this unburnt fuel that was knowingly pissed away. it doesn't work. the industry knew all along it didn't work...

go read the wiki and you'll say that i'm wrong but this is a reality based on misinformation again... if you doubt what i say try this... hold your hand in front of the cars intake air stream and see how long it takes to burn your hand... then do the same at the tail pipe.

i am quite certain that the gases emitted from the tail pipe will burn your hand before the air going IN to the motor.

so explain again how the EGR takes the exhaust gas and pipes in into the intake air and this cools the combustion charge...

that's not reality.

the EGR just displaces oxygen causing incomplete combustion and excess fuel cools the motor evaporatively. this is why you need a catalytic converter. (hasn't anyone wondered why all these computers still need cats to clean up unspent fuel? does anyone realize thats what the cats do?- they react the unburnt fuel and the by product is water)

land rover said "awww F_ _ K it let's skip the pretenses and the soot- we'll just dump extra fuel in to cool it"

like misting yourself on a hot day.

Disco mike- running rich (low octane) may add soot to motor a WITH EGR but with the rovers this is not an issue... higher octane is more dangerous to the motor because lean conditions can (and have- i have seen it and have a picture somewhere i can share) melt/eat/errode aluminum in the motor. usually you only see this when nitrous is used dry in an aluminum motor- but it does happen. lower octane does pose a risk to accelerating the clogging of the cats. (and this is the real reason for the octane requirements on rovers btw)


three last points to consider:

land rover states the same fuel requirement for both CR ratios available to the 4.0 (9.6 vs 10.3) ... 91.... 7/10ths of a CR point and no differentiation in the octane requirement? (no erg... octane is for the cats)

maybe owners (by which i strictly am referring to those who purchase NEW as this is from the eyes of LR) of luxury vehicles don't want their vehicles to be compatible with anything "regular"... it's been almost 10 years since the end of the D2. different world now. back then tho gas wasn't so pricey and "how premium can a vehicle be if it doesn't take premium fuel?" i joke, but also i don't

land rover is british, they do not ask for their cars to be filled with "premium" in GB and most folks refer to it as "high test"... JUST MAYBE when rover says "premium fuel only" what they REALLY mean is "use only quality name brand (FILTERED) fuel because we were too lazy to put a fuel filter on your truck"

i'm not saying run regular all day everyday even if you have the 10.3 CR... but it's buyer beware and there's a crapton of BS being thrown around by armchair engineers with Wikipedias address

 

Fuel Types - PetrolPrices.com

USA to UK , Petrol octane grading

acording to wiki premium is british for regular
Filling station - Wikipedia, the free encyclopedia
(see octane)

http://www.rockettbrand.com/techsupp...tisfaction.pdf

 

and yes i know knock sensors can cause timing to be pulled in addition to the fuel changes

 

when your arguing with yourself on line, it time to back away from the cafine

 

It's a four year old conversation. No one is listening.

Put what ever you like in you truck.

There is no EGR, so no point in pouting about it.

The engines run hot no matter which fuel is selected.

The throttle body heater prime job is safety to prevent ice up. If it was for critical for fuel/air mix calculations there would be another air temp sensor down stream from it. And later Discos would still have air intake under the hood (where it is warm) rather than thru the fender, etc.

Rover did put in fuel filters, either under wheel arch or in the tank.

Other members report small increase in mpg and smoothness of the truck running. It may be psychological, the reduced weight of the wallet does not press down on the lead foot quite so much.

WOT in my 97 is exhilarating - 0-60 in 3.2..... gallons.

 

Nice... I never want to read another 4 year old conversation that has fuel prices listed in it.

 

Haha yep

 

I recommend you just follow the instructions printed in the owners manual. No point arguing weather premium is better or worse for cars. I think it varies. Some cars need it accordingly and others just need regular. Some cars may get slightly improved performance or MPG but some cars notice no significant difference between regular and premium. So best thing to do is open your owners manual, look under the fuel door and follow the instructions printed. These trucks dont get great MPG anways and a couple cents extra for premium fuel really does not bother me. If you are that worried about saving every penny when at the pump then buy a Prius.

 

You want to learn how to replace head gaskets?
Then put in Regular for a year or less.
You'll get the idea.
Save .20 cents a gallon to spend $2,500 at a shop.
Penny-wise yes. Pound foolish - yes.