Thank for tip Rook. I will see if I have any problem in future. So far, I know I still have healthy engine right now. They already fixed gasket intake at 70K mile BUT the engine coolant didn't went into oil yet. My Oldmobile Cutlass Supreme did that. I got worse one. This car, I got lucky this time to noticed some leaking from value cover. It is now over 30K since repair. So far it is getting good (finger cross)

Hercman... can you give me example about how to solve the mpg? I'm suck with math lol

I usually fill her up when it is reach to 1/4. It is hard to tell how much empty tank I have?

MPG literally means MILES per GALLON.

you take how many MILES you drive, and divide it by how many GALLONS you used...

400 miles / 14 gallons = 28.6 MPG

I guess I will have to try that when I fill her up. It might take forever because I'm still on 3/4 since I fill her up last Saturday. That will be one week tomorrow

For example like

482 miles / how much gallon I fill her up usually around 15.80 something = mpg right?

You don't have to use a whole tank to get the mpg, but it provides a better average.

Just fill the car up, reset the odometer trip and drive. When you've used about half a tank, go fill it up again, note the gallons the pump puts into your tank and divide that by what the trip says. It's that easy.

i'd laugh if your sending unit is pooched and you run out of gas haha.

Something isn't right. Your tank is what, say, 15 gallons? 1/4 of that would be 3.75 gallons.

if you have driven 200 miles already and have only used 1/4 then that would be 200/3.75 = 53+ mpg...

even if that was all highway driving their is no way you would get 53+ mpg, even if you are going 55.

Sending units are odd how they work. The one in my GP hits 1/4 tank after 10 gals have been used and then drops fairly quickly. My Stratus stays above 3/4 until you hit around 130miles and drops fast for the remaining fuel.

Also, our tanks are 17gal.

Sound like easy to do that. I will do that next time when I fill her up to know what my mpg is.

I don't know if it is broken or I save lot of gas for new exhaust install? It is just reach to 3/4 this afternoon. It will be 250 miles when I get home from work tonight. I will drive it until fuel light come on to make sure that thing is working or broken. I will start fill gas tank can on trunk if I ran out this weekend.

That would be sweet if my car get 53+ mpg

1/4 of 17 is 4.25 and 200/4.25 is still 47 mpg.

i think it drops off fairly quickly at the end because of the shape of the tank. so lets go with 3/8 of the tank used rather than 1/4 because of the variance. 3/8 of 17 is 6.375. 200/6.375 = 31 mpg.

thats saying that he drove 200 miles (which he hadn't quite reached yet so that would lower the MPG) and saying that he used 3/8 of the tank (which we'll never know really know because of the variables). saying he used a little less gas like 5/16 turns out to be 37+ mpg i think.

31 mpg +/- 4 mpg (which i'm going to say is how much it could be off given the information we have) is right on par with what alot of modded 3.8's are getting on the hwy.

even with giving it a large benefit of the doubt, the gas savings is not really anything over a modded 3.8.

You might never know if my car is improving.

I will try again after I fill her up when it is hit low fuel light. I will start doing mpg math thing when I reset the trip mileage.

This car don't carry any items. My trunk is empty. Nothing on backseat. I use a/c sometimes during afternoon. I don't slam gas hard for "rabbit jump". Of course, I'm doing 55 mph.

If you think it is silly to keep 3100 instead swap 3800 engine because of gas saver. Well who know... In past 7 years after 9/11 attack. The gas price is keep rising and still going. Right now, it is getting improving go down but I heard it will rise back because of Texas oil problem during weather. I'm not future guy but who know if we might get like $4, $5, $6, $7, $8, $9 or more gallon

There are lot of change during gas price. Some of members sell gp for small car. Hybrid cars look like it is getting grow big. SUV & Truck are getting down. There are lot of small cars around. GM stop making V8 engine (I remember I read somewhere but I can't find link). That's probably reason GM stop make 3800 engine. It seems everyone going to make small engine instead powerful engine. I know it is suck have slow ass engine but everything have been change lot. Sh!t happen I guess. At least I'm not whine about my car mpg. I'm happy as long it is still good enough for 2 weeks instead week when I used be speeding freak.

I'm pretty sure GM still makes a V8.

It was month ago. I swear they will stop make by 2010?

GM invested money in the modular 60* engines with adjustable valve timing and went to larger engines (3.5 and 3.9ltr V6). They're still making tons of V8s, especially in trucks (4.8, 5.3, 6.0).

Anyway, a 3800 swap because of gas mileage is stupid. If his engine works and he's happy with the power, end of story. If he wanted more power... then we'd have a reason to lure him to the dark side. BTW, mildly modded 3800s get 30mpg... anything with a cam is another story unless you do some serious tuning.

No one ever said a word to Rook or any of the other guys about having their 3.1L motor. You bring this on yourself bu saying "good reason to not get 3800 engine". If you are going to dis our engine with the crap that you are typing, then we are going to disprove your faulty logic. If you just stop talking about it, we will let it go.

I don't know if anyone else pointed this out, but don't you have that backwards?

I'm not trying say bad thing to your 3800 engine. I just saying it might be bad because of fire and tranmisson blown but now I know everything. It is over with that. Like I say I would swap to 3800 engine if I have any problem with my 3100 engine. I get some of members trying tell me dump 3100 engine and get 3800 engine.

I got home tonight. My gas guage is now under 3/8. I hope it is really exhaust make my gas mileage improving or guage went bad. I have to wait until it is empty. It might be take forever empty that gas