So i noticed that Premium Gas lasts longer then regular..
On regular i get about 13 city/16 highway.
Premium seems to be giving me 14 city and 19 highway.. idk i only used premium once since my local shell station was out of the rest..
or i am on crack?
does premium last longer?

 

On a all stock engine normally from what I have seen... No mileage doesn't improve the 5.4 and V10 were designed for regular unleaded only with a high octane tune among other things would get anything out of the premium gas.

 

I dont notice a difference when going from regular to premium on any of my vehicles.... now when I add acetone, and I have been doing this for over a year with my 04 Explorer, she gets 28 highway and 20 around town. I havent tried it with the excursion yet. I have also noticed a big improvement when I add it to my 06 Explorer. Read about it on the net. It does work.

 

The higher the octane the slower the gas burns. If you have a vehicle designed for higher octane or you have advanced the timing beyond spec then you will see benefits from it. The slower burn will keep the engine from 'pinging'. The Ex in stock form shouldn't see any difference in performance - maybe a slight loss if anything.

59CRL - the acetone in gas is an interesting one.... pretty sure it's been proven to be a myth multiple times. What engine/trans combo do you have in the Explorer?

 

Well, what's *supposed to be* and what is, isn't always the same thing. I have a 2000 with the little 5.4 V8 and I've found it gets up to 2 mpg better with 93'ish Shell gas. No AC and keeping it under 60, I once got 17.6, but the best I've ever done with 87 in the 14 to 15 range.

When I towed my toy hauler loaded down on 87, I got 7.6 mpg. THEN, when I tried it with 93 premium, same distance, exact same route, I nearly got 10... finishing out the trip with 9.8 average.

I don't know why it does better on high octane, but with only 20 cents difference in 87 to 93, it's worth it to me to get the higher mpg AND it really does run better.

 

If it feels better do it
just do a google search for regular vs premium and we'll see you in a week when you finish reading

VERY few cars NEED premium, even if they call for it.
If it calls for prem and u put regular, you will have a FEW less hp....
and if you think the diff in price is worth it for the few ponies, then go for it !!!

mechanically sound gas engines now days ALL have knock sensors and will not knock...
electronics will change the timing to stop it before you even feel/hear it.

and just like tuners, additives say @ $4 / pint, MAY give you a mpg, but @ the cost of $12/gallon not worth it to my tiny pocketbook YRMV ...

 

The acetone isnt a myth, I was very skeptical at first, really scared that I would blow up my Explorer, but I add 1 ounce to every 5 gallons. So I fill up at 1/4 tank and add 3 ounces. My Explorer has the 4.0 V-6 and the 5 speed automatic I believe it is the 5R55..... I have seen a big difference in my Explorer, so I started adding it into my wifes 06 Explorer. She took her Explorer to her moms, 375 mile trip and told me she couldn't believe how good it did on gas.... her Explorer usually gets crappy mileage, struggles to get 19 on the highway, but it now gets about 25. Give it a try, it must be 100% pure clear acetone and only mix 1 ounce per 5 gallons.

 

Speaking of higher octane being better for the V10....I put e85 ethanol in mine a few weeks ago just to see what it does and man did it run great and it is 100+ octane.

 

I'm gonna kick my $.02 out there. Think of knock sensors they're on your vehicle to help the ECU control fuel and ignition right. Ok running 87 octane will yield you X degrees of advance. Your ECU will always try and adjust the timing as high as it can to gain better fuel economy, power, ect. Now if you run 93 octane in your vehicle you open up the higher ignition timing. Now your ECU will now be able to advance your timing higher.

I had a 2000 Expedition ran 87 for months with no issues. Switched to premium ran like a champ. Filled up with 87 a year later and knock / ping central it took it a few cycles to adjust back.

 

my wifes pontiac gtp engine management does that but I don't think the ford excursion do. gtp's will run agressive timing map til it hears detonation 10 times then it permanetly pulls timing til you restart the car.Not limp mode just a more conservative timing map.

Anyone else try the acetone trick?

 

There is a maximum amount of spark advance allowed from knock sensor input. When you hit that limit for advance, the PCM will NOT allow anymore spark no matter what the knock sensor input is. When the vehicle is tuned for premium fuel, it has spark tables that are setup for that fuel, then the PCM allows the knock sensor input to add timing up to that preset maximum. There is NOTHING to gain from using premium fuel in the vehicle if it's tuned for regular fuel.
JL

 

Not all. It's been reported on here that the 05 V10s (2 valve) don't have knock sensors.

 

That's absolutely right.
JL

 

I have a 2010 Audi S4 with a supercharged 3.0 V6 333hp/325ft-lbs rated at 28mpg HWY. The last generation (2008) S4 had a naturally aspirated 4.2 V8 making 340hp/302ft-lbs rated at 20mpg HWY. (both require premium which has less BTU's but is more resistant to pre-detonation in high boost or high compression ratio applications)

"Even though it lost two cylinders, Audi’s new engine gives up nothing to the old V-8. The six-cylinder has better low-end grunt and, according to Audi, 27 percent better fuel economy than did the V-8. The power delivery is linear, and the Eaton-supplied supercharger, making at most 11.6 psi of boost..." from: 2010 Audi S4 - Second Drive - Auto Reviews - Car and Driver

So what i'm wondering is, using the same concept, would a 5.4 V8 or even a 4.6 V8 with 11psi boost and running premium make the same power as my 6.8 V10 (in my 2004 Excursion Limited 4x4) all while providing much better fuel economy?

I was thinking I could try it out if my V10 ever dies... but it sounds like they rarely have problems.

 

I thought I read something somewhere that the Shell premium had no Ethanol in it. That might explain the better miliage more than the octane.

Perry