Why Honda CD 70 Never Gives 70 km/l Fuel Average

One of the most-viewed questions on the PakWheels Forum right now is the Honda CD 70’s fuel efficiency. 

That tells us that even after decades on the market, Pakistan’s most sold bike is still judged primarily on its economy. 

And it makes sense. When petrol is above Rs. 400 per liter, fuel economy is naturally the first thing on anyone’s mind when buying a CD 70. 

To address this, we are starting a new series where we answer the most popular forum topics using real-world riding experience and technical facts. 

Let’s start with the CD 70’s fuel economy, as it is our most-viewed discussion.

First, forget the 70 km/l Claim 

In the showroom, Honda claims a fuel economy of 70 km/l, but the real-world average, no matter how well maintained, will never reach this figure. 

That figure is more of a marketing or ideal-condition claim. 

So instead of chasing 70 km/l, the better question is: what mileage is normal for a healthy CD 70?

What Is a Good Real-life Fuel Average of Honda CD 70?

A properly maintained Honda CD 70 should return around 50–53 km/l with a single rider.

But this number applies only when the bike is in good running condition. The term “well-maintained” means:

• Air filter is clean and in good condition
• Engine oil fresh
• Chain is properly adjusted
• Clutch is working properly
• Ring piston is healthy
• Carburetor is tuned correctly

Why a Brand-New CD 70 Gives Lower Fuel Average

Before you panic about low fuel economy, check your odometer first. If your bike is brand new, the 50-53 km/l benchmark does not apply yet.

Every new bike needs a run-in period, locally called the “running period,” of 1,500 km before the engine reaches optimal performance. 

During these first 1,500 km, the engine’s metal components are still settling in. 

The piston rings need to seat properly against the cylinder walls, and all moving parts need to break in to achieve optimal clearances and surface finishes. 

This is why a brand new CD70 typically gives 40-45 km/l during the run-in period, jumping to 50-53 km/l after completing 1,500 km. Therefore, only check your bike’s true fuel economy after completing the run-in period. 

Why Chinese 70cc Bikes Give Less Fuel Average

The forum topic also mentions that Chinese 70cc bikes, such as United and Road Prince, often give lower economy than the Honda CD 70. 

It’s true. A normal Chinese 70cc has a fuel average of 45-47 kmpl.

The general assumption is that it’s a low-quality issue; there are two specific technical reasons behind it. 

There is a technical reason behind it.

The first reason is engine displacement. 

Chinese 70cc bikes use 78cc pistons compared to the 72cc pistons in the CD70. That’s 6cc more displacement, which naturally consumes more fuel. 

The second reason is sprocketing.

Both bikes use the same sprocket ratio: 14-38(14 teeth on the front sprocket, 38on the rear):

Bike Type	Engine Displacement	Front Sprocket	Rear Sprocket
Honda CD 70	72cc	14 teeth	38 teeth
Chinese 70cc bikes	78cc	14 teeth	38 teeth

This sprocket setup was made for Honda’s 72cc engine. Since Chinese bikes have larger 78cc engines, they have extra power that goes to waste due to an unoptimized sprocketing ratio. 

This means to hit 60 km/h, the Chinese engine is forced to spin just as fast as the CD70, wasting its extra power. And because a 78cc engine takes in more fuel and creates a bigger explosion on every single spin, trapping that extra power at high RPMs makes the bike feel overworked, and burn more fuel. 

This same sprocketing mismatch is also why Chinese 70ccs make more noise and vibrate more than CD70 at the same speed. 

How to Improve CD 70 Fuel Average

Now for the part everyone’s been waiting for, which is how to actually improve your fuel economy. These tips work for both CD70 and Chinese 70cc bikes, and they’re based on real riding experience. 

1. Increase the Front Sprocket to 15 Teeth

In stock form, 70cc bikes use a 14-tooth front sprocket. Replacing it with a 15-tooth front sprocket can help improve fuel economy.

Why?

Because the gears become slightly longer. At higher speeds, the engine runs at lower RPMs, which reduces fuel consumption.

The trade-off is that acceleration will reduce slightly. The bike may feel a little slower when accelerating in the 1st and 2nd gear.

This tip is highly recommended for Chinese 70cc bikes since it helps correct the sprocket mismatch we discussed earlier. 

2. Use 10W-40 Motorcycle Engine Oil Instead of 20W-40

Atlas Honda recommends 20W-40 engine oil for the CD 70. However, 20W-40 is a thicker oil, and most oils in this grade are mineral oils.

If your bike is brand new or has less than 10,000 km on the odometer, switching to fully synthetic 10W-40 motorcycle oil can improve fuel economy by 1-2 km/l. 

But there is one important warning, make sure to use only 4T motorcycle oil.

Do not use car engine oil in a motorcycle. Car oils contain different additives and detergents, and using them in a bike can cause clutch slippage because motorcycles use a wet clutch system, not a dry clutch like in cars.

Most 10W-40 motorcycle oils come in 1-liter bottles, while the CD 70 requires 0.7 liters. 

You can pour according to the markings on the side of the bottle and save the remaining oil for later use.

3. Use NGK G-Power Spark Plug

The regular Honda CD 70 usually uses a standard NGK spark plug. Replacing it with an NGK G-Power platinum spark plug can slightly improve combustion efficiency.

The G-Power plug uses a platinum tip that creates a sharper, stronger spark, allowing the fuel to burn faster and more completely. 

This means the fuel-air mixture combusts more efficiently, producing more energy from the same amount of fuel. You’ll notice the bike reaches peak RPMs more quickly, and throttle response improves due to improved combustion.

The Complete Economy Setup

First, make sure you’ve completed the 1,500 km run-in period. 

Then upgrade to a 15-tooth front sprocket (optional for CD 70 but recommended for Chinese 70cc), switch to 10W-40 fully synthetic motorcycle oil, and install an NGK G-Power platinum spark plug. 

Keep your air filter, chain, and carburetor properly maintained, ride with proper gear-shifting habits, and make sure tire pressure is 28-29 PSI.

With this complete setup, you can expect maximum economy from your bike, around 57 kmpl from the CD 70 and 50 kmpl for the Chinese 70cc: