Gas Mileage and Shifting

[RobbieD]

As with everything I try and research on the internet it seems impossible to get a clear answer. I want to know when is the best time to shift in a cougar to save on gas. Please only post if you have done some research on your own. I am well aware of what “everyone” says but it seems really car specific.

What I seem to have found out:
Shift between the torque and horse power peak.
Drive in the highest gear possible without bogging the engine down.
Down shift or let the engine slow you down. The added intake pressure uses less gas.
Drive slower as wind resistance grows nearly exponentially. 55 is better than 65mph.

What I really want to know:
Our torque and horse power peaks merge around 4000+ rpm's. That seems way to high to shift so when do you shift to get your best mileage?
What rpm do you drive at usually to get the best mileage?
Due to varying drag coefficients do our cars really need to go as slow as say a H2? I would think a .31 is low enough to cruise at 65 and not feel bad for burning too much gas.

That is all...

[ND4SPD]

I try to shift around 2000rpm... usually does pretty well for me.
I've also heard of this 55mph being better than 65, but I haven't personally tested that.

ChenZhen started a post a while ago in a quest for 30mpg, you should read up on it

[Goldie]

if you search old threads, there are a couple covering the 'ideal' shift rpm. IIRC, there was much debate and seems to really depend on your own personal driving style (but that also was a year or so ago - before fuel costs were more of an issue. So not as many people will probably be speaking up for the higher rpm suggestions I would bet .
personally, I shift between 2,500 - 4,000 depending on the speed, from what gear, accelerating or cruising, etc.

[bubby]

Originally Posted by ND4SPD

ChenZhen started a post a while ago in a quest for 30mpg, you should read up on it

Fixed that for ya.


I started shifting 500 rpms lower than I usually do (around 2.5k) and have increased my gas mileage by about 5 mpg's. It's weird you posted this because I was thinking about this yesterday.

[B3NN3TT]

For saving gas, you MUST stay out of the secondaries. This means you must shift before 3500. I've been shifting at about 3000 when I'm thinking about fuel economy. Otherwise, the engine bogs badly in the next gear.

[JScullin]

Shifting ~2,300-2,500rpms gets me glassy smooth transitions between gears. I'm avg 24mpg in traffic and 28mpg highway cruise ~60mph. Gentle engine braking helps too.

[JpFiZzAL]

i shift at 6 grand practically all the time. i love the way no cats sounds : )

[ND4SPD]

Originally Posted by bubby

Fixed that for ya.

Thanks!

[RobbieD]

Thanks for the good replies. Sounds like I'm doing things about right. I for sure keep the secondaries closed! I have been shifting about 2500-3000 and keeping 65 or slower. With 50/50 city highway I got 30.1 mpg with this tank. Let me say this, it's so hard to not let the cat roar sometimes.

Oh, it was good to see some of the long time NECO family post. I just about forgot about some of you. There are so many new people saying stuff thats just short of retarded. I don't get on here much anymore....

Thanks everyone!

[black cat]

I use to do 80 or 85 on the highway when i was using my girlfriends dads police gas card and i was gettin an average of about 20mpg city and highway, but now that i pay for my own gas i get on the highway and set the cruise for 55 and in the city i keep my foot out of it most the time and im gettin about 25-27mpg. point being is that when i get on the highway doin 55 it saves ALOT of gas. also in the owners manuel it says 55 is the best speed to save gas