Lexus ISF / IS-F / LFA / LF-A  Forum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter · #1 ·
Hello everyone,
Thought to ask people who have isf experience. Bought a 2008 isf recently. Great car. Only 2K miles. Amazing ride. Problem is that the gas tank from top to bottom only holds a max of 14.5 gallons. (Using my gas receipts) The estimator says 280 miles capacity when tank is completely full. Manual states the tank is 16.9 gallon capacity. Read other reviews which says their indicator states 300 some miles tank capacity when full. My average reading is 20.5 miles per gallon and I've been driving like a grandma (no offense to grandmas). Am I missing something here? Once the electronic guage says "zero miles" left is there still about 2 gallons left of fuel. Its driving me crazy. Keep driving from full to empty and keeps giving me the same readings. Thinking that there is some defect somewhere. Any help on enlightenment would really be appreciated.
Thanks.
 

·
Premium Member
Joined
·
439 Posts
Yes, I think there is right around 2 gallons left when the range indicators says 0.

BTW, the gas mileage gets better as the engine breaks in. Mine just passed 20k miles. I filled up today with 13.7 gallons after driving 305 miles...over 22 mpg. I took a trip recently, and averaged over 25 mpg on the highway even though I was in medium traffic most of the way and couldn't use cruise control.

Oh...also, after you fill up, the range indicator just puts your last range driven as your car's range. In other words, if you filled up after 255 miles, and your car said you had a range left of 25 miles, after you fill up you will have a range of 280 miles. If you drove 300 on that tank, it will guesstimate your next tank at 300 as well.
 

·
Registered
Joined
·
2 Posts
Discussion Starter · #3 ·
Thanks very much. That makes sense. Don't know if I want to risk trying to see if its really 2 gallons though.
 

·
Registered
Joined
·
294 Posts
I've drivin around on 0 for a few miles and no problems. There should be atleast a gallon left when you hit 0 if not more.
 

·
Registered
Joined
·
124 Posts
I'm pretty sure it's 16.9 gallons. I don't think Lexus would release incorrect specs on the gas capacity... Most manufacturer's have "reserve" so even though it says 0 there is typically a gallon or two left in the tank. Which would be the discrepancy between your readings and the actual tank size.
 

·
Registered
Joined
·
222 Posts
I filled up 16 last night which is the most I've ever had to put it in it.
 

·
Premium Member
Joined
·
439 Posts
At some point when I go on a road trip, I am going to focus on getting the maximum fuel economy possible. My goal is to get over 400 miles without filling up. I have gotten 25+ miles per gallon before in moderate traffic without using cruise control. I imagine if there was little traffic, a well broken-in ISF engine could easily get 26+ mpg driving at 70 mph on cruise control over flat roads. This would leave more than a gallon left in the tank at the 400 mile mark.
 

·
Registered
Joined
·
222 Posts
At some point when I go on a road trip, I am going to focus on getting the maximum fuel economy possible. My goal is to get over 400 miles without filling up. I have gotten 25+ miles per gallon before in moderate traffic without using cruise control. I imagine if there was little traffic, a well broken-in ISF engine could easily get 26+ mpg driving at 70 mph on cruise control over flat roads. This would leave more than a gallon left in the tank at the 400 mile mark.
I never have the patience on road trips I'm at 80+ the whole way passing every car I can lol
 

·
Premium Member
Joined
·
1,127 Posts
Yeah you never want to run your tank empty to 16.9 gal. It's normally to have 2-3 gallons when the light goes on. If you ever see 16.9 gal on a fill up, either you've nearly run the tank to fumes, or the gas pump at the station you're at is shady.
 

·
Premium Member
Joined
·
439 Posts
I never have the patience on road trips I'm at 80+ the whole way passing every car I can lol
I usually don't have the patience either. Today I did though. My wife and I were coming home to Baltimore from a vacation in Virginia. I drove very light on the throttle, and only about 5-10 mph over the speed limit....usually. Even though I made a poor route choice and took a highway (29) that made me stop at many lights while going through a few cities, I averaged 28.1 MPG over the 186 mile trip home!!!!!!!!!!!!!!!!!!! This was with some traffic, and rolling Virginia hills. I have no doubt that an ISF could average over 30 MPG on a road trip over flat terrain on a highway without traffic lights.
 
1 - 13 of 13 Posts
Top