OK, with gas prices fluttering here and there, I thought I’d see what I can do to reduce my petroleum spending. Since I splurged on a new fun car last year (2002 Mustang GT, convertable no less), I’ve been getting used to getting gas more often. But on the drive home last night I started wondering whether there’s a “sweet spot” in the engine where it’s at its most efficient regarding fuel economy. My complete WAG was that would explain why max torque and HP are given with RPMs.
I tried googling for information, but generally came to ads stating “XXX MPG and standard transmission”. So, what is the best shifting strategy to improve gas mileage?
Accelerating quickly to cruising speed, then stick it in 5th
Accelerate slowly?
And if I’m in slow traffic, would I be better off being in the highest gear possible without stalling? Or should I try to set the tach somewhere specific?
Or does it even make a difference, and I should start taking the bus?
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There’s no such thing as a stupid question, only stupid people
I would assume keeping the tach nice and low is the key.
Gunning the engine is asking it to turn over more, and thus suck down more gas.
It should make a difference, but I’d say if you’re really concerned, take that Mustang back and get a diesel Jetta.
(Not meant to sound holier than thou!)
Well, getting serious for a moment, there are some things that can be done to maximize fuel efficiency.
Set the tires at the highest recommended pressure. Note: this is NOT the pressure listed on the sidewall. Your owners manual should have recommendations on “continous high speed pressure” or something like that. An educated guess is it will be about 35 PSI.
Use the thinnest engine oil Ford recommends (probably 0W-30).
When driving accelerate swiftly (about 1/2 throttle) and skip every other gear, i.e 1-3-5. Shift at 3000 rpm. When driving at a constant speed use the highest gear that lets the engine run smooth. Your GT is a V8 and should run OK down to about 1200 rpm.
When you see a light turn red in front of you don’t continue at the same speed until the last second and then brake hard. Instead get off the gas and engine brake. Keep the rpm above 1200-1400 rpm during this (down shift if needed). Reason is modern engine management systems turn the fuel off completely during engine braking, and turn it back on when the rpms get close to idle.
The above DOES make a difference. I’d be interested in you posting your results…
The car has a lot of rolling resistance. You need to make double-sure that the tires are inflated as much as it is safe to do. For my GT with the 245/45 17’s (Goodyears) this is about 42 psi. But you need to confirm this on your own car.
This car has an engine that is much more free-flowing at higher rpms than the 1998 and prior ones (the 225 hp version of the 4.6). The things that are going to save you gas are:
Slow, steady acceleration.
Shifting to the highest gear possible as soon as possible. I find that I can cruise around at 30 mph in 5th without problem.
You can go to 0W-30 (I believe Ford actually recommends 5W-30 - at least they do for mine). The hard-core people recommend it heavily.
You might try posting your question to the Mustang bulletin board on Corral.net - it has a huge wealth of information just for your model year Mustang.
Basically drive so you don’t put yourself in a stop and go situation - leave pleanty of room so if the cars start to slow down you won’t have to brake and can maintain a steady speed.