I have a hard time believing this but it happened...
04-04-2005, 06:11 AM
#1
I have a hard time believing this but it happened...
Driving home from St. Louis, I managed to get 40.8 mpg. The speed limit was 55 so I was doing 59 the entire way. My car never broke 2,500 RPMs and was cruising at about 1,950 RPMs. I did 163.3 miles on 4 gallons of gas and I forced as much gas in the tank as I could. From there to my home, I managed 99.7 miles on exactly 3 galloons of fuel, again, cramming as much of the stuff into my tank as possible. On that leg of the trip, I was cruising at about 68mph. My girlfriend though I was a little on the crazy side for being so excited, lol.
~THT
~THT
04-04-2005, 06:50 AM
#2
Senior Member
Join Date: May 2004
Posts: 6,190
I don't believe it! You won't get an accurate assessment on fuel economy unless a) you drive further, and b) don't stop filling the tank up so frequently. You must have been going downhill all the way with a hurricane at your back.
04-04-2005, 07:07 AM
#3
Member
Join Date: Mar 2004
Posts: 88
Originally Posted by THT
Driving home from St. Louis, I managed to get 40.8 mpg. The speed limit was 55 so I was doing 59 the entire way. My car never broke 2,500 RPMs and was cruising at about 1,950 RPMs. I did 163.3 miles on 4 gallons of gas and I forced as much gas in the tank as I could. From there to my home, I managed 99.7 miles on exactly 3 galloons of fuel, again, cramming as much of the stuff into my tank as possible. On that leg of the trip, I was cruising at about 68mph. My girlfriend though I was a little on the crazy side for being so excited, lol.
~THT
~THT
Topping off with small amounts of gas is rife with variablity- fuel volume in lines, fuel rail and filter become a huge percentage relative to 3 or 4 gallons of fuel. I would estimate another half to 3/4 of a gallon or so you are not including do to this. In my estimation this would drop your MPG by 25% in your 3-gallon measurement - dropping 40 MPG to ~30. (about right-I've approached 30 few times in all highway driving).
04-04-2005, 07:23 AM
#8
Senior Member
Join Date: May 2004
Posts: 6,190
The reason I don't believe it is that I have never seen any posts remotely resembling the mileage you are claiming to achieve. The most I have ever had on the highway is 31.7 mpg and that was going 885 km (550 miles) with the idiot light on for ever and the car running on fumes. I filled it up until the gas was almost spashing on the side of the car. I have had 29 plus on numerous occasions on longer trips, but that is not exceeding 75 mph.
04-04-2005, 10:17 AM
#11
I have a witness although everyone here would claim bias as she's my girlfriend. Anyway, I posted my experience because I recognized it as a fluke. But that's not going to stop me from trying to repeat the feat. And no, the trip odometer is pretty accurate when compared to the posted distances.
~THT
~THT
04-04-2005, 03:52 PM
#15
Newbie - Just Registered
Join Date: Oct 2000
Location: Poughkeepsie, NY
Posts: 1,424
Originally Posted by joecraps
Yeah, hard to believe. Run full tank and do your calculations.
Topping off with small amounts of gas is rife with variablity- fuel volume in lines, fuel rail and filter become a huge percentage relative to 3 or 4 gallons of fuel. I would estimate another half to 3/4 of a gallon or so you are not including do to this. In my estimation this would drop your MPG by 25% in your 3-gallon measurement - dropping 40 MPG to ~30. (about right-I've approached 30 few times in all highway driving).
Topping off with small amounts of gas is rife with variablity- fuel volume in lines, fuel rail and filter become a huge percentage relative to 3 or 4 gallons of fuel. I would estimate another half to 3/4 of a gallon or so you are not including do to this. In my estimation this would drop your MPG by 25% in your 3-gallon measurement - dropping 40 MPG to ~30. (about right-I've approached 30 few times in all highway driving).
There are too many variables to get accurate calculations with that amount of fuel. Consider all joecraps said as well as the following contributing factors:
Different pumps shut off at different pressure
Tire pressure can affect accuracy of odometer
The more data you accumulate, the more accurate your findings will be. Try running a full tank, refilling at the same pump, using the automatic shutoff (don't top it off). Better yet, go through more than one tank and keep track of the mileage.
04-04-2005, 04:21 PM
#17
Originally Posted by TheFink
haha yeah, sure you did! 
~THT
04-04-2005, 05:54 PM
#19
Were you literally speaking when you said you were smashing the gas in the tank (like until it was pouring down your leg) or do you wait for the pump to stop on its own. Go on a longer trip try using the whole tank to get a more accurate measurement because if this is true I'll trade.
04-04-2005, 06:51 PM
#23
Originally Posted by THT
Driving home from St. Louis, I managed to get 40.8 mpg. The speed limit was 55 so I was doing 59 the entire way. My car never broke 2,500 RPMs and was cruising at about 1,950 RPMs. I did 163.3 miles on 4 gallons of gas and I forced as much gas in the tank as I could. From there to my home, I managed 99.7 miles on exactly 3 galloons of fuel, again, cramming as much of the stuff into my tank as possible. On that leg of the trip, I was cruising at about 68mph. My girlfriend though I was a little on the crazy side for being so excited, lol.
~THT
~THT
congrats, but be careful about cramming th gas into the tank. this may lead to an evap problem. we all do it, but you should fill up until the "click."
04-04-2005, 07:06 PM
#24
a couple times a pulled about 31 mpg on a 300mile road trip.
actually I just did about 345 miles to the gallon on about half a tank of gas,I noticed a better fuel consumption when I changed to NGK sparks @ .43 gap spec, was on Platimun Bosch before.
actually I just did about 345 miles to the gallon on about half a tank of gas,I noticed a better fuel consumption when I changed to NGK sparks @ .43 gap spec, was on Platimun Bosch before.
m
04-04-2005, 07:32 PM
#28
Senior Member
Join Date: Sep 2003
Posts: 887
I think its possible. When I was working for Volvo last year, I had to drive a S60R to an outing many hours away. I did 65 with the cruise control on the entire time and averaged 33mpg. The S60R averages 25mpg on the highway. If you were going 58mph, I can see you getting 40mpg. If you did your math correctly and drove on mostly flat land. 1,900 rpms is pretty damn low.
04-04-2005, 11:35 PM
#33
Senior Member
Join Date: Jan 2002
Posts: 874
It is most definetly possible. I routinely get around 30mpg on the highway. My record stands at 34.2 mpg, on a 300 mile trip with cruise set at 74mph (and this was with 180k miles on the car). Therefore, it stands to reason that at a lower speed of 59mph, as THT claims, even higher fuel economy ratings are possible. If the car is in excellent condition, not loaded with many passengers or crap in the trunk, if the weather was good, if there aren't many grades on the roadway, if you're using good fuel, if you use cruise control, and traffic was minimal, I see no reason why this couldn't be achieved.
As was said before, there are many variables at play here. Honestly, if you've never gotten above 28mpg on the highway there's a problem in your equation somewhere, and I'd first suspect people not using cruise control or just having a lead foot.
I hope this doesn't become another "what is your fuel economy" thread.
As was said before, there are many variables at play here. Honestly, if you've never gotten above 28mpg on the highway there's a problem in your equation somewhere, and I'd first suspect people not using cruise control or just having a lead foot.
I hope this doesn't become another "what is your fuel economy" thread.
04-05-2005, 07:42 AM
#34
ill agree its possible. My trip from PA to NY to pick up my crapnabi's from Freddie was a long ride, but with the AC at full blast, my subs in the trunk, and an extra passenger, i mustard 375 miles w/ 1/4 tank of gas left.
04-05-2005, 01:35 PM
#36
If all the variables are right I would not doubt it. Now imagine if OD or 5th gear in 5 speeds would be just a tad higher, so instead of hitting 2,800 rpm at about 70, we could hit about 2k rpm, it would be very nice.
04-05-2005, 01:42 PM
#37
Originally Posted by paultyler_82
I can beleive it, my brother's '04 525i was getting 42mpg the other day on one leg of the trip, tach didn't top 2500, that car has a MPG gauge in it to let you know what kind of mileage you're getting.
04-05-2005, 04:11 PM
#40
Newbie - Just Registered
Join Date: Oct 2000
Location: Poughkeepsie, NY
Posts: 1,424
Originally Posted by BigLou93SE
That's not an accurate way to tell gas economy - the guage you're referring to just tells the INSTANTATEOUS gas consuption, not the whole trip. Just look when he accelerates next time: even if he is using light throttle-acceleration, the gauge goes below 0 mpg. If he did it out, and divided the total miles accumalated on that tank of gas, by the amount of gas put into the car to get back to full, then he would know his gas mileage. But the way you described it, he did not get 42 mpg.