Increase MPG out of Skyactiv?

[svavrek]

Hey everyone. First post here! I have a 2013 Mazda 3 5 door M6, 2.0L Skyactiv. From Cleveland to Miami, I averaged 40.8 MPG... I want to try to pull 4-5 more MPG out of this sucker but am not sold on the short ram or cold air intakes. K&N claims a 3 MPG (+/- 1) increase for the $50.00 filter. Anything that is warranty friendly that can be done other than this? I have a feeling this thing can see 45 average MPG on highway... Oh, once I get to ~70mph I set cruise then reset the average fuel economy and let it calculate while on cruise driving down Rt 77.

Thanks!

 

[nasa779]

Simple, drive slower. at 60-65 youll have less wind resistance and boom instant fuel economy.

Otherwise, theres always that secondary air filter in the top of the airbox that isnt replaceable you could cut out.

 

[ceric]

Pump the tires up to 40psi.
Maintain good alignment, clean air filter.... all simple stuff.

 

[theorist]

I want to try to pull 4-5 more MPG out of this sucker but am not sold on the short ram or cold air intakes. K&N claims a 3 MPG (+/- 1) increase for the $50.00 filter. Anything that is warranty friendly that can be done other than this?

What others said about speed and tire pressure are dead on.

About cheap and easy MPG increases from a $50 filter or $100 CAI just think critically: if Mazda could have increased the gas mileage by even 2 mpg by spending another $40 to $90 more on the air filter, wouldn't they have done so? Were the Mazda engineers incompetent, the Mazda accountants that cheap, or the aftermarket pitch men full of it?

High flow air filters can make a difference with performance with wide open throttle, that is with the gas pedal pressed down all the way, by allowing the engine to bring in more air and fuel to create more power. But if you are driving with the gas pedal all the way down, I hope you probably aren't concerned about fuel efficiency at those times. The gas pedal controls the throttle which restricts air flow into the engine. If the throttle is restricting air flow already, it doesn't really matter if the air filter is too unless the air filter is really dirty and clogged. Driving with a more restricted air filter is not much different than driving with a lighter foot on the gas pedal.

I drive a 2012 Mazda3 hatchback with Skyactiv and a manual transmission. On long highway drives, I consistently average over 50 mpg as long as I keep my speed below 60 most of the time, the roads are dry, and the weather is above freezing. The only 'mods' contributing to this are highly worn tires inflated to 44-42 psi (but a larger and less fuel efficient tire size than stock: 225/45R17) and a ScanGauge to help me drive more efficiently (displaying real time gallons per hour, engine load or throttle position, ignition timing, and trip mpg).

There's a rich community of hypermilers out there who make a sport out of maximizing their fuel efficiency. Some of the best guides are written by Wayne Gerdes, who goes by the username xcel at cleanmpg.com. Look him up if you really want to increase your fuel efficiency.

 

[concept]

Think twice about increasing tire pressure beyond a few psi, for the following reasons:

1: The center of the tire tread area will wear out, prematurely, forcing you to buy tires, sooner than normal. You may end up wiping out any fuel savings.
2. By overinflating, the tires' contact area with the road will be decreased, which in turn, decreases traction on dry and wet roads.

 

[ceric]

Modern vehicles have alignment setup such that, front tires wear outer edges, while rear tires wear inner edges.
Tire rotation can balance the wear inner and outer.
What about the center?
Unless you inflat them beyond 50psi, wearing middle is not going to happen severely.

The only downside is bumpy ride. For which I think GT is already at my wife's upper limit.

Check any Prius forum. These owners inflat their tires beyond 44psi. No abnormal wear observed.
Try PriusChat.com.

 

[concept]

Personal experience tells me otherwise. With just 5 psi over the recommended 30 psi for my Corvette's tires, center wear was obvious and dangerous. I was behind a guy in a 96 Corvette when he spun around on a curve. When asked how that could happen when he'd driven that route dozens of times, previously, he couldn't give an answer until he checked his tire pressure. It was 5 -7 psi higher than it normally was, and that wasn't high to begin with. My MX5 is the same way - stay within +/- 5 psi and the handling is great, but go much more than that and a wipeout on a damp road is much more likely.

 

[theorist]

That's a very good point of caution about higher psi. I have noticed some decrease in straight line dry traction with higher tire pressures. FWIW, TireRack and CarandDriver (or was it another mag?) documented improved wet traction with slightly increased tire pressure. Initial turn in response and even cornering stability can be improved with slightly higher tire pressure. Of course it all depends on the car, the tire, the road conditions, and how much pressure we're talking about.

Personally I prefer highly inflated summer performance tires to OEM LRR tires at manufacturer specified tire pressures. I may not get as good gas mileage, but the traction and handling are MUCH better than with the Low Rolling Resistance OEM tires. I've never had a tire wear in the center as fast as on the sides, but then I usually accelerate moderately, brake as far in advance and as little as possible, and take turns as fast as possible. So higher tire pressures work well with my peculiar driving habits.