VJZ

iTrader: (3)

On the way back from Tennessee I blew a tire running my 17" rims. I had the OEM spare on one wheel and on the way back was running 80MPH consistently. I only filled up the top half of the tank and was able to knock down 28MPG, as confirmed with my buddies Prius with stock wheels and tires. I had used 9.4 gallons and had went 258 miles.

I got home, put the stock wheels on, and now am getting less than 20. I drive to work on a two lane 55MPH highway and over to my fiancee's place every night on a different highway with the same attributes.

I JUST did a tune up involving plug wires, plugs, cap, rotor, and VCG's. I have an axle back custom exhaust on the car as well. I rarely speed and drive very conservatively and cannot understand how I can immediately be sipping fuel to hogging it.

blackops

On the trip getting 28mpg were you following behind someone closely? That's called drafting dude. If you're within 2 seconds of a brick (like a prius) doing 80mph, you'll def see a major increase of fuel mpg.

VJZ

iTrader: (3)

No genius. My trip ODO was off because of the larger diameter rims I had. His car was accurate and I knew how many gallons I used

DaveGS4

iTrader: (2)

My guess is you're doing a lot more mixed city driving on scenario 2 vs the first pure highway scenario 1. More stop & go, more in-city driving to get to work or home vs fill up and just drive straight on the highway.

I wouldn't discount the following another car for that entire period as a factor if you did do that in scenario 1 - that does make a noticable difference in mpg but moreso if it's a truck vs a smaller car like a Prius.

VJZ

iTrader: (3)

I was not following cars (or the Prius) on the interstates of my trip. I just was behind average traffic but left ample space in between. IE, I don't tail anyone.




I guess I can outline my trip to work daily:

leave home and travel two miles out of town to the State Road (55mph) for ten miles with two small towns that slow speeds down to 45 on the way. One stop sign on this road. I then turn onto a 65MPH highway for two miles, and then off onto a 35MPH street in South Bend where everyone goes 45-50 anyway. There are stop signs and lights on this road, so thats the city driving. T

To my lady's home:

Leave town and hop on 55MPH highway for eight miles and turn left onto side street and take that to her subdivision. It just seems like it could do better.

Could I have a vacuum leak? I could only get the car to run right if I switched two hoses around. Occasionally, the TRAC light comes on but goes away if you stop the car and restart. it doesn't seem to be bogging.

I can't figure out the vac lines though, its complicated.

TheMole

iTrader: (13)

Did you put the spare on the front or rear?
If you put it on the rear, the spare might be lighter and not as wide as the
17" wheels so there is less resistance when driving.

mitsuguy

iTrader: (2)

I've had similar results with my driving... constant speed is key to fuel mileage...

DasBach

iTrader: (7)

I personally don't see any problems here with what your stating. I drive a steady 55 to base each morning, but to go to San Diego for example, its a steady 75~ and I average about 25-27. In town, even if I don't rag on it I still only get around 20, if that. I've read these same results numerous times... it sounds normal.

blackops

Our single 1jz SC gets it's best fuel MPG around 11.7% throttle, or 78mph. Around 32mpg.

Bring it down to 45-65, and it will drop to around 22

5sp_jzz30

iTrader: (2)

you gas mileage situation is totally normal.

i drove last night from drift day. i had 4 wheels and tires in the back seat. a few bags, a passenger, and trunk completely filled with tools. going about 80mph i got 22mpg. when i got home and unloaded everything and drove to school on my own i got about 25ish going 75ish.

in the city i get between 22-24mpg.

all this on supra tt wheels with 235 front and 255 rear.

wired wheels and tires create more surface area and reduce your mileage. the wheels are probably heavier then stock too so that will as well.

StiCk3

iTrader: (5)

what kind of wheel were you using at the time? its probably going to be heavier than the stock wheel unless your running something super light like Volks or something. After running on stock 16s for the winter i got around 23-25 avg. When i put on my summer rims (50 lbs w/ tires BTW) it went down to 19-20 mpg...a lot of rotational mass...i need new rims....

There must have been something we're missing here because one wheel shouldn't give an extra 8 mpg...how much do the 17s weigh?

CCC-TT

iTrader: (1)

i believe the stock spare is heavier than the stock 16" wheels. But i dont know what to tell you, one time i recorded 29mpg highway with my mom in the car to vouch. we filled up at a gas station and zeroed out the Trip ODO, then drove maybe 10-15 down the highway and then pulled over and filed up again and then i did the math which came out to 29mpg, i was surprised.