Hello,


With the stock automatic trans, I was getting 26mpg. I did a 5spd swap and now I only get 24mpg at best.


I have done several tank fill ups and now always average 24mpg.


I thought it was my driving habits, but I shift at 2500rpm. No mashing of the gas pedal.

 

try hypermiling, always being in the highest gear possible. Like say 5th gear going 40 in my '97 5speed is 1500k rpm (my VSS is going out, cruise and speedo work intermittently, waiting for the time off work to fix it)

I'm not even sure how my car does on gas, I'll gauge it for a couple days and let you know.

 

That's what you get for thinking that your brain is able to control things better than an ECU can.

 

Did you exchange your ecu to one intended for stick shift?

 

If you look at the factory rating for these cars, the automatics are rated at one mpg better than the manual on the highway.

I believe that this is because the auto has a taller final gear so at 70 mph the manual is at 3k rpm or so and the auto is around 2.7k.

I'm sure someone else can chime in to give exact info on the rpm vs mph in the final gears for each car.

As for improving your mpgs i suggest shifting at like 1800 rpm and do not red light race.

 

No, still running the auto trans ECU.

Only trouble codes are the missing auto trans.

 

9 times out of 10, a manual trans equipped car will yield better mpg.

The weight difference is huge between the two transmissions.

 

The vss is really easy to get to just be careful with the one bolt that secures it...I just went to change mine 2 months ago and the head of the bolt snapped off. RIP tacho 😭😭

 

Yup, from factory, the 4th gen 5MT has worse highway MPGs than the auto. 3000 RPMs at about 80 mph in 5th gear will do that to you.

 

Yup. more gears, weighs less. Despite all that, it's the 5MT gearing that hurts the mileage. Nissan chose the gearing to keep the fun factor going in all ratios. 5th gear is really like a semi-overdrive. I'm sure you noticed how the car is much peppier and responsive on the highway now than before.

This is also one the reasons why the 6MT conversion is so popular. 5 forward GO gears and one laid back mpg gear gives our cars greater mileage (some guys have seen 34 mpg) and better forward acceleration.

 

I'm getting 26ish mpg with mostly city driving. I make sure to up shift whenever I can. Our cars have enough torque to use 5th gear at lot in the city. Its perfectly fine going 25 in 5th gear. I think we might get better mileage at 30 in 5th than 70.