Hello everyone. My MPG is a little wacked out right now. I am getting really good city and main roads mpg(30-50) and on average i get anywhere between 18-22
but the problem is freeway I get 20-22 every time now. I drove several tanks just to be sure it wasn't cold weather. (we get 50-60 degree days right now) I have done this with cruise on and with it off driving like a granny. dont accelerate hard hold at 70-75 miles per hour braking as little as possible just babying it. When i first got the car 10,000 miles ago, i was getting 28-30 mpg driving 80 miles an hour driving hard on it. flooring it while merging, breaking when someone was going to slow merging then flooring it again and then repeating. just having fun. any ideas to what is wrong. Maybe low fuel pressure
bad spark plugs?(dont see why they would be bad plugs they were brand new platnium ones that have 10,000 on them). engine just needs a good cleaning? (used some k&w fire lock on it to seal a head gasket. It fixed it but i didnt know how bad it was for the engine at that time.)

thanks for any help

 

ive gotten 35 highway doing 70 lmao fyi make sure its full completely pegged and at the line just before E mine is at like 3.5 gallons left this is my car specifically your may be different.

 

oh mine is brokenish for a gauge i get 12 gallons till its on E. but then i have exactly 4.4 gallons left after that. and it reads the 1st quarter tank is like 4 gallons then the 2nd quarter is 2 gallons the 3rd is 1 gallon and then the 4th is 5 gallons.

But on the other note which of all the above mentioned, in my first post, would best be related to my mileage problem. I am not enjoying only getting 20 to gallon freeway and then 22 city

 

honestly that seems impossible to get 20mpg highway and 22 city....

 

Something isn't right here.. I can hardly get over 28 MPG EVER.. even if I do 100% freeway driving. And your city driving should definitely be lower than your highway.

 

Yeah, those mileage figures don't sound right. How are you calculating your mpg? The best way to figure it is to divide the mileage recorded on the trip meter (reset at every fillup) into the gallons required to fill the tank. You can't rely upon the onboard computer calculations...they're not very accurate.

 

yeah i get anywhere from 16-19mpg city/freeway driving and around 28 if its all highway

 

Agreed, i've been calculating fuel economy since the begining of october, every fill up. The highest i ever got was 26.83mpg. Granted its a mix of highway/city but its about 80/20% respectively. (this is why im jealous of L67 drivers for getting 30+) And like mike said, divide miles driven by gallons it took to fill the car and that should give you an accurate result unless your speedo/odometer are off.

 

i assure u it isnt my math thats messed up. i top off every fill and then divide the miles by the gallons used. its typically 250 when 12 gallons are used sometimes a little more. My city driving is mixed with main road driving too, so i drive between 30-50 mph. when i drive freeway i get 240-250 per tank and that is just about the same mileage and thats driving between 65-75 mph. The first few times i drove this freeway i consistantly got 30mpg and that with all the stuff on my car. Right now I am getting these numbers with an A/C delete. In all logic i agree that this is impossible but i kept accurate record over the past month and i consistantly get 20-22 for both city/main road/freeway

 

I`m doing alot of freeway driving right now and my `98 is getting 33 mpg with the cruise on. No a/c running. I need new tires but they`re inflated to the right pressures. It`s a 3.1. No issues with it. You didn`t state total miles on your engine but mine has 142k on it and everythings fine. I use SeaFoam in my fuel every 1000 miles or so. You may have a carbon build-up issue. But I also run mid_grade fuel always. Hope this helps some.