CLRH2O

So the check gas light popped on after a COMPLETELY full 93Octain fill up a few days back.... I checked my Trip-o-meter - which I've been using these past few months on each tank and the numbers have been fairly similar each time - and it showed that I'd driven 265.4 miles.....

This seems low to me.... I'm not sure off hand but isn't our SC400 tank 15 gallons? That's like 17.6 MPG - is that good or bad?

It's a mix of City and Highway driving as well. The city is only partially rush hour and the highway is in general 70Mph 30 mile runs point to point - just to give a little background on the driving being done. I'm not a lead foot either and the car is BONE Stock with 109k miles and a new OEM air filter (put in @ 107k)....

What's the word on this? Thank you in advance for any info

SC_coupe

EPA gives it 18 city, 22 highway. Either your foot is a bit heavy or your economy is a bit low. My SC400 is pretty bad on gas, but then again, I've been accelerating faster than I should. There was just a thread on this a week or 2 back. Some suggested a new fuel cap on the older cars improves mileage slightly. I'm going to give that a try, along with a new fuel filter.

vwynn

iTrader: (4)

what rpm do you usually let ur car shift at?

my dad got 26 miles a gallon. From Corona to Sandiego.. (freeway mostly)
while we get like 17-18 mostly city..

np20412

SC tank is 20.6 gallons, dont worry my mileage in my SC3 is just as crappy, i'm lucky to get 300 (~15mpg) miles to a full tank around town. On a highway only tank I can get close to 400 per tank (~20mpg) averaging no lower than 80mph with heavy acceleration while passing. I'm sure if I kept it at 60-65mph only I could get closer to 450 miles per tank.

XxSC400xX

iTrader: (1)

Around 17 MPG with mixed driving sounds about right. When the gas light comes on you have around one or two gallons left in the tank, I've never run out of gas so I don't know for sure. Things you can do to try to improve your gas mileage would regular maintenance like spark plugs/wires, distributor caps/rotors, o2 sensors, seafoam, new fuel cap, checking tire pressures regularly and removing any unnecessary junk in your car. Remember the SC400 is a heavy car with a V8, gas mileage will never be that great.

sc-driver

iTrader: (7)

wow you guys are lucky.

The way I'm driving, I get around 9-12 mpg. But then again I only do city driving and have a heavy foot
Its so sad when I go put gas, the trip odometer doesn't even go past 200 miles.

itssr20

My highway mileage went up on my sc4 when i did stage one of the BFI (cutting a hole in the airbox and removed the snorkel)

ryansong

yeah with a full tank i get around 220 or a bit more. ALL city driving in a sc300. suuuckks.

The Ikon

My old 92' SC4 use to get about 26 mpg or more on the hwy at respectable speeds.. If i remember correctly.. In the city it was about 18-20 mpg. It sounds like tune up time...

https://www.clublexus.com/forums/sc-1st-gen-1992-2000/32048-the-hell-with-mods-is-your-sc-running-right.html

Plus, ease off the gas pedal a little and no jack rabbit starts... Save a few mpg and $$$

CLRH2O

Thanks for the info everyone. To reiterate I did state that I am easy on the acceleration ("I'm not a lead foot") so that's not it.

The car was bought from the Mercedes dealership in Tampa on Oct 7th last year (5 months ago) and they showed in their papers that it had received a tune up ..... but I'm very suspect of that now.

lxsdude

Remember that the EPA ratings are for the engine alone not in a car and with no accessories on (radio, A/C, windshield wipers, lights, ...etc.).

You're getting better gas mileage than most people I would think. The main thing to remember here is don't believe everything you read on the brochure.

chuggernot

I figured with the EPA ratings in the news so much lately everyone would know that those "estimates" were rated high. A lot of people were complaining that they could never get those numbers in their new cars so the EPA is revamping the way they get those figures. Personally, I say to hell with gas mileage and just enjoy the ride.

The Ikon

Every dealer has a different "TUNE-UP" given to it's cars. Some just change plugs, some change wires and plugs, some filters etc... AND don't forget about that fuel filter... so often over looked, because it is under the car! The plugs could be improperly gapped, bad or cheap wires... dist cap etc...

Throttle body/maf unit clean? All vacuum hoses connected? Is the coolant good and running cool?

Also DUMP the stock air filter and buy a K&N panel factory replacement improves MPG and performance... Check tire pressure and tire condition.. Use a synthetic blend oil in the car and a good quality oil filter... The same for the tranny...

And your car should get that good mpg as it once did...

https://www.clublexus.com/forums/showthread.php?t=32048

acenase

something is wrong if you are getting 9-12 mpg. those are what Viper's and Heavy duty trucks get. Not what an SC should be getting.

You don't need to fill up your tank when you see the low fuel light, that thing goes on when you have like 3 gallons left.... You are good until the line goes BELOW the "E" letter. So you should be able to see the full "E" above the line before you have about a gallon left.

The tank is 20 gallons, so what you should do is when you need to fill up record how much gas you are actually filling up and where the line is on your Gas meter. Sometimes I think my gas is low but when I fill it up I only fill up 16 gallons, so that means I could've went 4 more gallons to my full tank which is almost 80 more miles.

CLRH2O

I had no idea that our tanks are 20.6 gallons (still haven't located factory shop manuals and the car didn't come with it's original owners manual). I'm only using around 16 each time it looks like......

I'm actually really glad I asked this question - as simple and often talked about as it may be.