Excellent Gas Mileage

Messages
523
Location
Illinois, USA
I have been away for a few days to a wedding in Kansas. I filled up my car yesterday there and drove all the way back to Illinois and got 385 miles out of the tank in my 1998 Ford Mustang GT before I had to fill it up again to make it the rest of the way home. There was some speeding involved. The best I ever got prior to that was 350 miles out of a tank which was all highway miles like the Kansas trip. I am curious why it improved so much. I wasn't driving slow. I did change out my Mobil 1 EP 5W-30 SL to the SM version before I left and ran Shell premium gas. Anyway, I just thought I would share.
 
Messages
1,527
Location
Mid-West, USA
Well, some gasolines are better than others. Some gas has ethanol, and some gas has oxygenates. You may have gotten just pure gasoline with neither. This would probably give the Mustang some better MPG.
 
Messages
2,338
Location
Charlotte Metro area
Warmer weather? Hot air is less dense, so there is less drag on your car at highway speeds. Also, because hot air is less dense and therefore contains less Oxygen per unit volume, your ECU sends less fuel through the injectors (runs more lean), giving you better economy. Plus, maybe the fuel quality has changed.
 
Messages
5,429
Location
KC
I live in the kansas/missouri area in south KC and its because of the gas. Both missouri and kansas dont use the 10% ethanol in the regular 87 octane, just regular gas.
 
Messages
13,228
Location
1/2 hr N.E. of Detroit
Shell Premium is the best premium out there. It works well for most vehicles -- but not all. Since it contains the highest amount of cleaners for your injector(s), well it may have improved the passageway in your gas line. When I purchase regular gas, I get Marathon. I feel it's the best in that lower octane category. Mid-grades are a waste of money. They should also be 90 octane for that price ... not 89.
 
Messages
1,550
Location
North Texas
Buford... What is your calculated MPG? (miles driven / gallons used) This past weekend there was a front moving eastwardly across the plains, so that likely helped as well. How many miles you got per tank is only relative assuming your fill-ups were done in similar fashion (filling until the pump shuts it off) and a MPG calculation is better than just going by amount of miles diven as a guide to mileage.
 
Messages
195
Location
Colorado
Too many variables to know for sure! If your car was angled at that particular station it may have taken more gas than other fill-ups. In my Dodge, angle is enough to change fuel economy 2 MPG. Depending on where in Kansas, you may have been going downhill for a while and not realized it. Kansas elevation drops as you head toward the Miss. River. Gas formulations are another possibility. -brian
 
Messages
3,398
Location
Midwest, Illinois
quote:
Originally posted by Triple_Se7en: Shell Premium is the best premium out there. It works well for most vehicles -- but not all. Since it contains the highest amount of cleaners for your injector(s), well it may have improved the passageway in your gas line. When I purchase regular gas, I get Marathon. I feel it's the best in that lower octane category. Mid-grades are a waste of money. They should also be 90 octane for that price ... not 89.
777, I totally agree.. Marathon is good stuff.. I got some on the way to NY, and got excellent mileage over the three tanks I used. For 89, I will blend 50/50 premium and regular. Same price as the point spread, maybe (most likely) more cleaning agents, and should be 90 octane. I also look for the pumps with dedicated hoses for each grade. That way I know if I select premium, I'm getting it, not a hose and pipe full of regular from the customer before.
 

Al

Messages
19,233
Location
Elizabethtown, Pa
As pointed out sometimes miles per tankfull are not meaningful. When I do on my 335 mile trips to WV, I really don't know the score until I fill up down there and then just before coming back I'll fill up and check it when I get home. I have been on a roll for the last 1.5 years. It usually averages 35.5 +/- 1 mpg. Wind, rain, and temp are good for +/- 2 mpg easy. Also elevation is significant. I typically get 1 to 2 mpg more coming home.
 
Messages
2,154
Location
New Hampsha
I've been getting better mpg since April which happened to be the time that all gas in this area went to 10% ethanol. Summer gas blend must have hit then also..doesn't make sense that the ethanol would be the cause as most people complain about it. Went from 300-325 miles per tank to regularly over 400...I must admit that I'm slowing it down a bit now trying to keep it under 3K on the highway and avoiding fast starts and stops. Avg probably 35-36 mpg now as opposed to some tanks in the winter that netted me 28-29 [I dont know] I'd like to think the Castrol Syntec Blend that is in there now had a role in the mpg increase (same time I changed oil mpg went up) [Cool] Goose [Patriot]
 
Messages
506
Location
ATL
i actually believe that texaco/chevron has the best gasoline. Why else would all these manufacturers use it in their testing? and all grades- including 87 have techron. Texaco sells chevron gasoline at a discount price!
 

Buford T. Justice

Thread starter
Messages
523
Location
Illinois, USA
I filled up on Shell premium in Concordia, KS. I remember it was rated 91 octane. I always fill up my tank with as much gas as possible without overflowing it. I took I-81 up to US 36 and headed east on it all the way to Hannibal, MO where it 'merges' into I-72. I was starting to get worried when I was getting close to Hannibal but saw there was still enough gas left to make it to Barry, IL where I filled back up with Shell premium. In Illinois, it is rated 92 octane. Anyway my Mustang has a 15.7 gallon tank approximately according to the owner's manual. It took 15.2 gallons to fill her back up so... 385/15.2 = 25.3 MPG Not bad at all for a 1998 Ford Mustang GT. The drive had some speed, but we were going 75 - 80 MPH on average. I had to go to KS for my brother's wedding so I had a buddy riding with me (who owns a 1995 Ford Mustang GT I use to own) and we had more friends in a GMC Yukon following us and vice versa (we pass each other for fun and to relieve boredom, lol). My friends in the Yukon thought I was crazy pushing it and my buddy in my car was cheering me on. My parents were in a 2004 Chevy S10 not far behind us so I figured if I ran out they could give me a ride to get some gas. Anyway it all it fine and I was shocked to get that kind of mileage out of that car. My buddy wanted to try it with his Mustang. Now I usually use Shell premium when I take long road trips like that. The best I had ever got before that was 350 miles out of a tank and that was never speeding. This 385 mile tank did have speeding and I did get up to 100 or better a few times to pass my buddies in the Yukon back after they passed me. I also recently went to Mobil 1 EP 5W-30 so that was more than likely a factor as well. Going 75-80 MPH was giving my car RPMs in the very low 2,000 range. There are lot of hills in KS, MO, and IL. Lastly, I filled up in Hannibal, MO with Shell premium on the trip to KS. The car got 338 miles out of the tank before it had to be filled up again. I think the town we made it to was Belleville, KS. We were going faster on the trip there as opposed to the trip back home. I guess it was good gas and good oil. I was just astounded it got 385 miles out of a tank of gas. My friend that was riding with me thought I was B-S'ing him about getting 350 out of a tank so 385 was a nice surprise for him and myself. My car is an automatic. His (which use to be mine) is a manual.
 

Buford T. Justice

Thread starter
Messages
523
Location
Illinois, USA
I forgot to mention that I didn't see any ethanol stickers in KS. There is 10% ethanol in the gas here in Illinois. Also it was funny seeing the corn and soybeans get bigger and better looking going from KS back to IL, lol.
 
Messages
1,759
Location
Elizabeth City NC
I get significantly better milage with shell premium. I have also found that tire inflation is the best improvement you can make in your milage. Mine goes up 2mpg with an extra 6lbs in each tire on my Accord.
 
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