Weight reduction / MPG / Eco Modding

[iaw]

Hi,

I'm a new owner who's interested in performing some Eco modding (with limitation due to a baby on the way, ie I can't change the interior). I have a 2014 Sonic LT sedan and I've already pulled the spare out and I don't have a lead foot

I've done some research on the boards, but it seems like things are pretty scattered and I may have missed something so here goes on some ideas I'm considering (my main goal is weight reduction).

1) MPFabs battery holder and smaller battery (is there anything better than the Fit battery I've read about?)
2) Catback exhaust (does it have to be cat back or can I simply get something lighter than the stock exhaust ... hp isn't a concern, neither are looks really)
3) Seibon hood/panels (not sure if the back panels are the same for the sedan and non-hatchback)
4) K&N CAI (I've read this can improve MPG by keeping the air used in combustion cooler, but I'm assuming this ranks lower on the list)
5) LRR tires ... going to be a tough one to justify at first unless I can sell the existing tires and then get the new ones.
6) Trifecta tune, but I assume I'd want items 2 and 4 done first or is there a gain for stop and go driving from stock setup?

Given that I can't tear the interior apart, are there any other standard stock Chev Sonic parts that can be replaced by aftermarket lighter (usually aluminum I assume) parts to help reduce the weight? What about hoses? Etc.

I'm almost exclusively a stop-and-go driver so I'm really trying to reduce weight since that's what matters most. Every pound counts ... I'm also looking for alternative options (rather than just K&N or top notch exhaust systems since looks isn't a concern, function is).

 

[spacedout]

I found with the spare tire out the ride/handling suffers, you feel allot more of the bumps with no weight on the rear suspension as well as the rear not feeling as planted.

Its to bad you can't touch the interior, Removing the rear seat on my hatchback was around 50lbs and since it was weight mounted higher in the car, effected the handling more. Car stays much flatter in the corners with the seat removed and spare tire in place.

 

[iaw]

Yea, unfortunately we bought 2 new cars, an SUV and the sonic. The wife is keeping the SUV for most of the day to day stuff with the upcoming baby while I'm taking the Sonic, but I NEED to have the interior as is in the event that I have to pick the baby up (which will happen a few times a week for sure).

I'm really focused on engine/body mods that will reduce weight. As for as the body goes I think I can only get a few carbon fibre panels, not the trunk yet, I can't find a grille block and the tires are brand new, but I'll try and sell them for some LRRs.

I've read different engine parts on some cars can weight up to 5lbs (for some reason the example I remember was a crankshaft pulley), I know I'd get almost 10lbs on the battery ... I'm just aiming for whatever anyone can come up with.

 

[spacedout]

The little stuff will add up, you could pull one rear headrest, and floormat if you only have one kid. Take out the owners manual(down load the PDF to your phone). Those three things might not seem like much, but probably total 5lbs.

When I was taking weight out of my Sonic I weighted everything I took out, with all my camping gear and rear seat out, it was over 130lbs off my car. I have all that wight back now however since my MPG was only 1-2mpg better at best, I still average 37-38mpg with everything in my car.

Driving habits and route changes will pick up more MPG than any lightening you can do.

 

[cndctrdj]

1) MPFabs battery holder and smaller battery (is there anything better than the Fit battery I've read about?)
2) Catback exhaust (does it have to be cat back or can I simply get something lighter than the stock exhaust ... hp isn't a concern, neither are looks really)
3) Seibon hood/panels (not sure if the back panels are the same for the sedan and non-hatchback)
4) K&N CAI (I've read this can improve MPG by keeping the air used in combustion cooler, but I'm assuming this ranks lower on the list)
5) LRR tires ... going to be a tough one to justify at first unless I can sell the existing tires and then get the new ones.
6) Trifecta tune, but I assume I'd want items 2 and 4 done first or is there a gain for stop and go driving from stock setup?

1. The mpfab stuff is amazing. If you are going to get the battery tray you should probably get the intake and dp as well for better gas mileage. Getting rid of the cats will go far with fuel mileage.
2. The rest of the exhaust you can get from anyone. I've never seen a comparison but I'm sure the aftermarket stuff is lighter.
3.the hood fenders and hatch are all nice and light. Im.pretty sure you can still get them. But if you have a sedan I'm not sure they sell a trunk.
4. Kn is ok the mpfab is a better unit but the kn is plastic so it is probably lighter
5.car comes with lrr tires from the factory
6. Get a tune from bnr. Much better.

Onto stuff you missed.
1. Porting the intake manifold. This one is tricky. The intake has baffles in it. The restrict airflow. It kills mpg. But it also tumbles the air, that helps at low rpms. It's something you will have to do research on
2. The belly pan. On early sonics they came with a belly pan for better mpg.
3. A few other gm eco cars have more underbody pans. Get them and fit them to the car.
4. Find a diffuser. Or make one.
5. Fill in the spaces between the headlights.
6. Lower the car.
7. Bigger air dam
I'm sure I'm missing stuff. But this is a good start

 

[spacedout]

5.car comes with lrr tires from the factory
6. Get a tune from bnr. Much better.

Onto stuff you missed.
1. Porting the intake manifold. This one is tricky. The intake has baffles in it. The restrict airflow. It kills mpg. But it also tumbles the air, that helps at low rpms. It's something you will have to do research on

5. The Hankook Optimo H428 Is not a LRR tire, I had a cruze with 16in wheels before the sonic, over 100K I had three different sets of tires ALL of which rolled much better than the 17in hankooks on my sonic LTZ. One Hill I drive daily 45mph at the top in the cruze, was 73mph at the bottom(left in 6th gear no brakes), Sonic under the same conditions only hits about 65mph. You should have seen me the first 100 miles in the Sonic, I would let off the gas to roll up to a stop sign only to have to get back into the throttle because I slowed down to much!

6. Tune does not add MPG, only way it could would be a decrease in engine load under slight loads/hill grades. Under most conditions however you will see less MPG especially if your using that new found power.

1. Porting the intake would be detrimental to MPG, as those turbulence crating baffles are there to increase low RPM torque quicker turbo spool up and throttle response. Sure you will gain top end power but again that's not where you drive for MPG.

 

[cndctrdj]

5. The Hankook Optimo H428 Is not a LRR tire, I had a cruze with 16in wheels before the sonic, over 100K I had three different sets of tires ALL of which rolled much better than the 17in hankooks on my sonic LTZ. One Hill I drive daily 45mph at the top in the cruze, was 73mph at the bottom(left in 6th gear no brakes), Sonic under the same conditions only hits about 65mph. You should have seen me the first 100 miles in the Sonic, I would let off the gas to roll up to a stop sign only to have to get back into the throttle because I slowed down to much!

6. Tune does not add MPG, only way it could would be a decrease in engine load under slight loads/hill grades. Under most conditions however you will see less MPG especially if your using that new found power.

1. Porting the intake would be detrimental to MPG, as those turbulence crating baffles are there to increase low RPM torque quicker turbo spool up and throttle response. Sure you will gain top end power but again that's not where you drive for MPG.

Was unaware the tires were not lrr. They are some of the worst tires I've ever been on. I assumed that was the reason.

A tune will most certainly gain you mpg. Let me rephrase that. A good tune will most certainly gain you mpg.

From my understanding. The tumblers are only there to help with startup airflow and are detrimental to everything else. I'm not an expert on this but from reading in the forums it seems to be the case

 

[spacedout]

Was unaware the tires were not lrr. They are some of the worst tires I've ever been on. I assumed that was the reason.

I'm not a fan of Hankook tires, had bad luck in the past with them as well. Mine are already needing replacement before 30K miles, in fairness though I've never got more than 30K from any stock GM car tire.

 

[cndctrdj]

The tires suck Haha. No two ways about it.

 

[iaw]

yea, I know I need to replace the tires but I have a hard time justifying the cost right now when there are other upgrades (like the tune) that could be done first. Though I'm keeping my eye out for a summer tire sale soon (I live in Eastern Canada).

As for the tune, I've seen the Trifecta has a transparent mode and that's why I mentioned over BNR because my car still has 3 years left on the warranty. Does BNR have the same thing? Trying to read up on them now.

 

[cndctrdj]

Swap back to stock before work

 

[RMinNJ]

Don't get the Continental Pure Contact tires.. great traction but noisy and they hurt my
gas mileage.

 

[iaw]

Don't get the Continental Pure Contact tires.. great traction but noisy and they hurt my
gas mileage.

Wow ... those are exactly the ones I had my eyes on as they're highly rated.

 

[The Champ]

Wow ... those are exactly the ones I had my eyes on as they're highly rated.

I don't know anything about the PureContacts, but I've got the TrueContacts on my company car and I'm very happy with them.

I put them on in early December and have put about 35,000 miles on them already (I drive a lot for work). Quiet, good in the snow and the rain.

You're looking at spending a lot of money in an effort to be more fuel efficient.

With that thought in mind (reducing fuel consumption), replace your wheels with the lightest ones you can find and them mount the lightest LRR tire on them.

Lower unsprung weight will improve handling and fuel efficiency...:banana:

 

[cndctrdj]

Also was just thinking. If you tuft test each section of the car and figure out what the worst part is. It would help a lot

 

[TheGreenDragon]

...replace your wheels with the lightest ones you can find and them mount the lightest LRR tire on them.

Best Chevy OEM option is the 17" Chevy Cruze ECO rim. 17 lbs of forged aluminium and they bolt right onto the Sonic. Best part is, you can usually find someone selling a set for cheap over on the Chevy Cruze forum.

Best aftermarket option is Sparco Assetto Gara. Sadly these are a bit rarer now that Tirerack has discontinued them. A 16" set of these run 16 lbs per rim. Weight goes up with diameter. Make sure the set has a 5x105 bolt pattern.:banana:

 

[RMinNJ]

Yeah the continental pure contacts got a good gas mileage and noise rating on tirerack...I don't know how...they are noisy..they sound like snow tires..at least on the sonic. And with that traction I think gas mileage suffers. But they do handle and grip well...those parts of the reviews were true. I will be putting them back on in the winter...they have a good snow rating..

 

[texsprsonic]

I'm running a set of continental extreme contact d.w.s 06 tires. the road noise is pretty minimal and the grip is excellent yet my mpg has not suffered. I've got the Trifecta Elite tune on my 1.8L and i can average 44-47mpg in the city if I decide not to race it around lol

 

[Bastion]

Another quick easy item to remove...
The rear seat headrests. Together that's 5 lbs saved right there! Plus you get the benefit of more rear view visibility! I don't need them because the only passengers I'll ever have In tow are my small kids... so headrests unnecessary!