Honda Accord / Acura CL shift points and right cruising gears - Fuel Economy, Hypermiling, EcoModding News and Forum

IvanAndreevich · 05-17-2009, 02:39 AM

Does anyone know how to drive a stick shifting Honda car with a f22/f23 engine most efficiently? I.e. Honda Accord 94-97, and, in my case, Acura CL 97-99.

1) When accelerating, what RPM is the best to shift in each gear?
Shift too low and it's terrible for fuel consumption since the engine is very inefficient at the low RPM. I tried shifting at 2K and it sucked ass. Slow and bad fuel economy.

2) When cruising, above what speed does each higher gear becomes more economical than the previous one? E.g. I am going 40 km/h and I can't go faster (traffic or crappy road etc). Is it better to be going in 2nd, 3rd or 4th gear? Car can drive in all. Or going 60 km/h. Is it better to cruise in 4th or 5th? Etc.

When I first got the car, I was getting 9.3L/100 km (25.2 mpg) but I have recently improved to as much as 7.3L/100 km (32 mpg). This is around 90% city driving - we don't have crap for highways around here. I'm doing pulse and glide, and just staying off the brakes as much as possible in general.

SVOboy · 05-17-2009, 03:26 AM

You're probably doing something wrong if shifting at 2k gets you bad fuel economy, because in that car I would likely shift there or sooner and skip 4th gear.

It's always best to be in the highest gear your car will drive in at any given speed. This is also true uphill.

Good luck

IvanAndreevich · 05-17-2009, 04:09 AM

Quote:

Originally Posted by SVOboy

You're probably doing something wrong if shifting at 2k gets you bad fuel economy, because in that car I would likely shift there or sooner and skip 4th gear.

It's always best to be in the highest gear your car will drive in at any given speed. This is also true uphill.

Good luck

Sorry, do you have any idea what you are talking about?

This car will drive at 30 km/h in 5th gear if I am absolutely flooring it. This will give absolutely horrible fuel consumption. BTW, I do skip 4th gear if I can accelerate to a speed in which I can drive in 5th.

I should drive in the gear in which my throttle is most closed. And that's definitely not the highest gear in which the car will drive in every situation.

I went from 9.5L / 100 km to 7.5L / 100 km by shifting higher while keeping my other practices the same.

SVOboy · 05-17-2009, 04:47 AM

Well, you asked. Sorry if you don't like the actual answer. If you have to floor it to drive 30 kmh there is something wrong with your car.

hummingbird · 05-17-2009, 02:31 PM

Hi Ivan, I followed this thread to get my own best results. I am sure it will give you your best results too. All thanks to SVOboy.

You certainly can do much better than what you are doing, because your vehicle has EPA ratings of 25/31 mpg city/highway. Typical hypermiler would get anything between 20-70% better than EPA.

Accelerate between 2100 and 2700 rpm and follow P&G aggressively. Keep your tyres at near sidewall max pressure. All the best and let us know the results.

MetroMPG · 05-17-2009, 08:03 PM

Ivan: do you have fuel economy instrumentation? ScanGauge or OEM?

To answer #2 (the ScanGauge would tell you this, which is why I asked), in every car I've ever driven, the highest gear you can cruise in will give you best results.

PaleMelanesian · 05-18-2009, 03:50 PM

On both of my Hondas - a 96 civic 1.6 and a 2004 Odyssey 3.5 - the best mileage comes below 2,000 rpm. Basically, lower rpm is better, so long as you're not flooring it just to keep moving. Three-quarter throttle and something below 2k rpm is great.

hummingbird · 05-19-2009, 01:45 AM

PaleMelanesian, is your advice valid for P&G as well? Because SVOboy's observations on crxmpg.com as posted above indicate exactly the opposite...

PaleMelanesian · 05-19-2009, 10:26 AM

Actually, we agree. SVO's test shows that there is a limit to how low rpm and throttle you go. Notice that his "jackrabbit" test was 50-60% throttle and max 2000 rpm except for first gear. That matches my advice very closely.

Read this article. It helps explains the why.
Autospeed BSFC

hummingbird · 05-19-2009, 11:55 AM

Yeah... looks to be that way indeed! In my first reading I was distracted by the attractive title byline, as also the temptation to enjoy the best of both worlds... Not to mention the 2500 rpm shift point for the first shift.

No wonder I was stagnating if you disregard the seasonal dip for the summer AC use. Thanks for the clue Pale, my next tank could be something to look forward...