Ways to improve MPG?

[benjerman112]

what o2 sensor do i get for my cb w/h22a4 obd1. thanks

[Shag Wagon]

Heh you can get a passenger mirror delete...less drag

[johnl]

My CB7 (a manual car) has done 42mpg on long highway runs (carefully checked).

My secrets (in no particular order):
Well maintained engine.
40+psi tyre pressures.
CAI (might help a little?).
Toe set 0 / 0 front / rear.
Synthetic gearbx oil (Motul).
Remove power steering belt (significant improvement in mpg).
Drive sanely.

Note that this engine is an f22A9, which has a higher compression ratio than the f22A6. Higher CR = more efficient combustion with more power / less fuel consumption.

[K2e2vin]

I understand higher compression gets better MPG; but I really don't feel like doing much to the engine internally(ie, milling the head). If it comes to that point I'll probably try to swap a smaller motor into the car(SOHC F18 or F20).

I was already thinking about removing the P/S pump, I guess I'll go ahead and try that. But...I'm also going to reinstall A/C(previous owner removed it). He claims a gain of 5mpg but I doubt that; as he said the A/C compressor clutch was messed up.

I've ran high tire pressures before but with bad luck; I had blow-outs with otherwise perfect tread(Kumho 758 and "Formula GT" tires at around 42psi IIRC). I'm just sticking with keeping it around 35psi.

[npor]

If you swap a smaller motor into the car you'll just increase your mpg.

It's like my Mercedes...it gets 12mpg, 4.6L v8. Now, I'm sure if I put a tiny V6 in it..my MPG numbers would drop, because of how HEAVY the automobile is.

[K2e2vin]

The Accord is not that heavy.

You're MPG would only drop during acceleration since it'll theoretically take longer/more throttle to get to speed. That's it. The amount of power it takes to maintain cruise speed is not that much.

Also, your comment insinuates the Accords that came with those motors get worse MPG than the 2.2l USDM Accords. According to Wiki(which I do not know how accurate it is), the fuel consumption of the F18A translate to 30.5mpg; which is a little better than the 28hwy our cars are rated.

[npor]

I know it doesn't compare to my 450sel, by any means. What I was getting to, is if you put a smaller motor in a car, without changing the weight, you'll more then likely see worse mpg's. The accord is that heavy, for an import, tuner-type car.

[lokuputha]

40+psi tyre pressures.

sweet.

This helps a lot towards low mpg, but the tires better be in good shape, otherwise, get ready for some slippaage.

[K2e2vin]

I don't look at the Accord as a "tuner" car.

I'll take my chances with the smaller engine. The Camry of similar years(93-96) weighed more than the Accord btw(3000-3300lb), and the Altima weighs about the same(around 3000lb). Later DC2 Integras were roughly the same weight as DX coupes. IMO, not bad for a larger car.

[90Haccord]

The Accord is not that heavy.

You're MPG would only drop during acceleration since it'll theoretically take longer/more throttle to get to speed. That's it. The amount of power it takes to maintain cruise speed is not that much.

Also, your comment insinuates the Accords that came with those motors get worse MPG than the 2.2l USDM Accords. According to Wiki(which I do not know how accurate it is), the fuel consumption of the F18A translate to 30.5mpg; which is a little better than the 28hwy our cars are rated.

Since when are CB7's rated for 28 on the highways?

fueleconomy.gov indicates 26 mpg for mine.

[d112crzy]

fatboy's F20B(that I tuned) gets 40+mpg with one of the shortest transmissions ever.

[K2e2vin]

Since when are CB7's rated for 28 on the highways?

fueleconomy.gov indicates 26 mpg for mine.

Same website indicates 28mpg for mine. I drive a 5spd.

We've had instances of higher MPG with shorter transmissions on D-series also. A guy with member name "Aquafina" is getting 47mpg with a MFactory close ratio kit and 4.9FD on a D16Z6 and I hit 57mpg with a DOHC ZC transmission and 4.25 FD(soon to be 4.437) on a D15B VTEC using p28 basemap.

[Losiracer2]

Since when are CB7's rated for 28 on the highways?

fueleconomy.gov indicates 26 mpg for mine.

I got 21 29 for mine looking at the Car and Driver archives but I got a high of 32mpg w/ the A/C going in the summer time (100+ degree temps) I avged around 30mpg straight highway after I fixed my headgasket a couple months later. So I'm thinking about 30 is good for a well maintained engine. I even have 17s on there w/ wider tires, so if I were to use 15s w/ 195 tires instead of 215s, i'm sure it might go up too.

[johnl]

sweet.

This helps a lot towards low mpg, but the tires better be in good shape, otherwise, get ready for some slippaage.

I don't know if it helps "a lot" with economy unless the starting point is quite low, but it certainly helps.

If by "slippage" you mean grip, then it's something of a myth that grip decreases as psi increases. The higher the psi (within reason) the better the steering and handling response tends to become, and (in my experience) the grip level also increases. There is a point beyond which grip does tend to drop away, but it's different with each tyre and fairly high, typically either approaching the max psi (as marked on the sidewall) or at the max sidewall psi.

Of course what psi works best for tyre X may not work best for tyre Y, and even if we fit the same tyre on different cars the optimum psi may change. Finding the best pressure with a given tyre fitted to a given car is a matter for experimentation. My experience is that the tyres which respond most markedly to increased psi are those with excessively soft sidewalls.

[Losiracer2]

I don't know if it helps "a lot" with economy unless the starting point is quite low, but it certainly helps.

If by "slippage" you mean grip, then it's something of a myth that grip decreases as psi increases. The higher the psi (within reason) the better the steering and handling response tends to become, and (in my experience) the grip level also increases. There is a point beyond which grip does tend to drop away, but it's different with each tyre and fairly high, typically either approaching the max psi (as marked on the sidewall) or at the max sidewall psi.

Of course what psi works best for tyre X may not work best for tyre Y, and even if we fit the same tyre on different cars the optimum psi may change. Finding the best pressure with a given tyre fitted to a given car is a matter for experimentation. My experience is that the tyres which respond most markedly to increased psi are those with excessively soft sidewalls.

don't forget about the rubber compound as well. A V speed rated tire doesn't have as much grip as a ZR rated tire.