Gas Milage...sc300 vs. sc400
02-05-07, 09:55 PM
#31
Lexus Test Driver
I think I got about 25 in a 92 SC400 with 153k-- plugs/wires/cap+rotor status is unknown at this time--
I got that going a steady 78 to 80 mph on fairly flat terrain--
I got that going a steady 78 to 80 mph on fairly flat terrain--
02-06-07, 06:26 AM
#33
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I average a pretty consistant 20mpg with almost all highway in my 92 SC300. (Of course, I average ~85mph all the time too 
). I was able to get ~25mpg by slowing to 65mph on a long trip w/ no air once...
I will definitely be changing my gas cap... the one on it is from a honda.
). I was able to get ~25mpg by slowing to 65mph on a long trip w/ no air once...I will definitely be changing my gas cap... the one on it is from a honda.
02-06-07, 09:56 AM
#34
I always get mpg within the EPA mileage estimates for my '94 SC400 (18 city, 22 hwy). I usually get right at 20 mpg for mostly city driving with a little highway mixed in. The highest mileage I ever got was just over 23 mpg with all highway driving. It dropped below 18 when I was having a computer problem and the ignition timing was being retarded. Once I had the computer overhauled, the mileage was right at 20 mpg again. I don't consider the mileage bad for a car with 200k miles and a V8 engine and relatively old technology, but I sure would like to be getting 30+ in the city and 40+ on the highway like my brother's (non-hybrid) 2006 Honda Civic Coupe!!! But then again, that's a completely different type of car --- and I still do love my SC!
02-24-07, 11:41 AM
#37
I just got my SC400 about 2 weeks ago.... I know fuel economy wasn't great, but it really likes the premium gas. The gas shortage here in Ontario doesn't help things either. My car is a '92 so I guess I should get a new fuel cap... maybe that will help things.
02-24-07, 07:50 PM
#38
Awhile back i posted about a hissing sound coming from my gas cap like 4-5hrs after the car was parked/turned off.
So when I was at Lexus, I told one of the mechanics about it. He told me that the same thing happened with his wife's ES and some jargon about air in the fuel tank and pressures...bottom line change the gas cap...reset the computer
I did and no B.S. my MPG went up. Hey, I didn't believe it either..Either it worked or Achmed the "gas fairy" lives in my trunk
So when I was at Lexus, I told one of the mechanics about it. He told me that the same thing happened with his wife's ES and some jargon about air in the fuel tank and pressures...bottom line change the gas cap...reset the computer
I did and no B.S. my MPG went up. Hey, I didn't believe it either..Either it worked or Achmed the "gas fairy" lives in my trunk
yeah i get htat hissing noise when i uncap the gas cap at the station i guess all the pressureis built up...it doesn't hiss when im not driving but i guess thats a good sign that pressureis not escaping cus theres so much when i uncap it!
02-24-07, 08:51 PM
#40
Keeper of the light
iTrader: (17)
SC's SUCK at gas mileage. My Benz has 275hp/300tq and outweighs the piggy SC by a long shot, yet it still get's 5 mpg more than my sc400 (and runs circles around it).
Still, I love the dang SC enough to own a couple.
Still, I love the dang SC enough to own a couple.
02-25-07, 01:21 AM
#42
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will the fuel filter make a big diff? i still have the original one. Also i read at the beginning someone talking about tire pressure, alot of people including myself does not check the pressure on a regular basis. What are the correct numbers where they should be at?
02-25-07, 11:02 AM
#43
im pretty sure correct numbers are 32? about there..
and ive been told that chaning the fuel filter helps a lot..
when we dot a new filter.. u can blow into it and youll actually feel air coming through it but with the OLD one there was NO air coming through it was completly clogged... iono how the filter works besides filtering gas.. but im PRETTY sure it will save u gas
right now im using these MPG caps.. and imma see if it will gimme more miles per gallon
and ive been told that chaning the fuel filter helps a lot..
when we dot a new filter.. u can blow into it and youll actually feel air coming through it but with the OLD one there was NO air coming through it was completly clogged... iono how the filter works besides filtering gas.. but im PRETTY sure it will save u gas
right now im using these MPG caps.. and imma see if it will gimme more miles per gallon
02-26-07, 02:26 PM
#44
after reading this whole entire thread, I have to conclude that there is not really a MPG difference between both SC's 18-23 should be it in most cases. Thats not bad for a V8 though.
As far as the gas cap theory goes, I thinks its BS unless the gas cap is damaged meaning when you fill it up at it will not hiss when you open it.
As far as the gas cap theory goes, I thinks its BS unless the gas cap is damaged meaning when you fill it up at it will not hiss when you open it.
