how you nt guys getting 35-40mpg?

[justnobody]

hey whats up, anyways, i was reading old posts and I saw NT even turbo guys getting 30+ mpg. What are you people doing to get that great gas mileage? I have a 99 gs .. generic cai(soon to be aem sri), megan cb exhaust, and im getting 25mpg 85% of my driving is highway too. It has 115,000 miles on it so i guess that might be one problem. idk its getting me mad, I do alot of traveling cause of work, so i sold my mustang which got me 22mpg and had balls for a gs which is intirely too slow and not getting much better gas, i mean i dont mind it being slow if i had good gas mileage. Im getting my car rebuilt in a month or so, any suggestions, for better gas mileage?, i checked the O2 senor, the air filter is okay, and i watch my foot i know theres other things i just cant think of it right now..

 

[19Eclipse90]

My mother's 98 GS would get consistent 35 mpg on the highway. It was completely stock and never threw CELs. We just sold it with 117K on it. Something isn't right though on yours; there is no trick to getting 35mpg, the cars just do unless they have problems.

 

[TheAdvocate]

I had a GS that got about 30-32 mpg on highway. It was a stick and driven right..

If you can stay out of the throttle it will help But my GST got 28mpg on highway, and im running 750 injectors/20g turbo.. But if im in the throttle, I drop down to about 22 on the highway.

 

[Locke]

Your generic CAI does the same thing as the AEM SRI. I really hope that AEM sticker is worth an extra $200 to you.

Make sure your clutch is not slipping, and accelerate gently. Use a decent copper core spark plug, with a proper gap.

Give the motor a Seafoam treatment. Excessive carbon build-up in the cylinder can cause hot spots to form, leading to pre-ignition/knock. The ECU deals with knock by pulling timing, which reduces power. Reduced power means you have to lay into the throttle more to get the acceleration you expect, which requires more fuel.

Since you spend most of your time on the highway, and you are going to be doing work on your vehicle soon, consider a Neon transmission with a 3.55:1 differential, and a 0.72:1 fifth gear. This will put you ~550rpm lower at 65mph in fifth compared to your current transmission.

 

[cbrue122]

I recently went through a drawn out tune up on my 97 GST and it has exceeded my expectations in terms of gas mileage. The most recent long highway trip I averaged 35mpg! The tune up started with replacing a bad engine coolant temp sensor which made it run rich and drastically affected mileage. However, when the temp sensor went bad it threw a CEL; something you did not have (although I noticed the rich running symptoms a few weeks before the CEL). One thing you could check though is if the sensor is the true Mitsubishi unit or a generic one. I ran a generic temp sensor for a couple months and started getting bad startups. I switched it out for the Mitsubishi unit and gained 5 mpg; no joke! The rest of the tuneup consisted of NGK iridium plugs, Magnacore wires, and a new oem replacement Bosch o2 sensor.

 

[roadrunner2176]

97 non turbo, 44 mpg highway, 36 mpg city.

Stock transmission
Stock engine
Manual 5 speed.
140,000 miles

Dont accelerate hard, shift under 3000 through all gears, Keep your fluids in check, change or blow out your air filter when you change your oil, proper gap on spark plugs, avoid excess weight (dont be hauling god knows what around with you everywhere you go unless its necessecary), tire inflation, wheel alignment, 02 sensors.

Those are pretty much the basics, regular gas works just as well as premium in these cars,(NT) so dont think it helps any to buy premium, and dont always be on the pedal. Let the engine slow you down, be in the right gear.

You might feel like a turtle when you accelerate, but if your highway driving you wont be accelerating that much anyway. If you have your stock parts and some spare time do a test, something like x amount of miles with stock parts vs aftermarket parts and see what you come up with.

A neon final gear would help on the highway, but when you do some city driving you wont be able to put it in 5th and just let the car pull itself along at about 14-1500 rpm just touching the pedal. Another thing to consider about the neon 5th gear would be that your 500-600 rpm lower than normal, not sure here but that could impact the stress on your engine causing you to require more fuel to lessen the load on the engine.

 

[19Eclipse90]

For the record, my mom's car was auto and would get 35mpg even fully packed with stuff, 2 adults and two kids in the back seat. It was pretty consistent.