Gas Mileage

[lwilliams24]

What can we do to get better gas mileage out of the Silverado SS? What can I buy to improve besides a cold aire intake, and exhaust? Any more ideas? Any small things I can do?

[eamonnschevy]

what kind of gas mileage are you getting? i'm getting 10.7mpg and at $9.00 a gallon over here in the UK.

I find less right foot on the throttle works quite well. red light races are now for weekends only lol and sedate driving when going to and from work helps, but i didn't buy the SS for its economy, i have a 07 mitsibushi Lancer station wagon for when the weathers not so good,or if I want to take the dogs out, but since gas went UP again i'm alternating use with the SS, not as much fun but loads cheaper.

If you find the secret to good gas miles be sure to post on here,

all the best

eamonn

[sonickoolten]

10 mpg???? holy crap!!! i get bout 15-16 mpg and gas is bout 4.30 fo premium..... get a beater for like 500- 1000 bucks or get a motorcycle has been working wonders for me about 14 bucks to fill up all the way and i get 35-40 mpg and its a 4 gallon tank

[scooter3]

I am getting about 17 - 18, but most of mine is highway driving. Light on the pedal, keep the tires inflated properly and use nitrogen if you can find it. Pretend the truck does not have brakes. This keeps you from hopping light to light. Good luck.

[SSPOSSE]

What can we do to get better gas mileage out of the Silverado SS? What can I buy to improve besides a cold aire intake, and exhaust? Any more ideas? Any small things I can do?

 

cleaning the maf sensor will help keep the mpg up.. iam getting about 15.5 in city and highway, i have not been on roadtrip yet since the new cpu... will be going on a roadtrip this weekend but then that info will be thrown out the window..since this weekend iam installing e-fans,160 stat, and a zippy tune.. i will give you the info on the roadtrip bac and on how much difference.. but the cold air box intake mod will you give a bump right up front for the buck..

Edited June 18, 2008 by DSM04BLACKSS (see edit history)

[Turbocoop]

If youve got a lot of miles Id recommend cleaning the TB out and running some fuel injector cleaner in there

[misterp]

There's LOTS you can do -

 

EASY -

1) tune the AFR to 15.2:1 (no leaner) in the 6-8 cells that you do all your cruise/light throttle driving, this alone will get you 2-3 mpg improvement and when done right is no risk of engine damage or change in driveability; also the GM tune is PIG RICH during throttle transitions and WOT operation, obviously done for reliability but it's overkill;

2) get a tonneau cover, the lighter the better even the fabric ones will gain very significant mileage over 45-mph;

3) make sure your basic tuneup is spot on, prime fuel wasters are dirty air cleaner, MAF sensor, plug wires, O2 sensors, tire inflation;

4) run Mobile-1 0W-30 motor oil (or equivalent AMSOil or RP) rather than 5W-30; run good synthetic fluids;

5) install a shift kit, Vette 2nd servo, and then reduce shift times to .2-.3 seconds and torque management down to 10%;

6) install a set of efans;

7) drop weight - get a rollpan, trade the spare for reliable tires and a AAA card, get forged 20" rims, clean all that crap out of the back seat = 200+ lbs savings

 

ADVANCED -

8) install a used Radix supercharger (good for 1+ mpg improvement at cruise);

9) have belly pans made for under the truck, this is as big a mpg help as the tonneau cover;

10) aerodynamically close all leaks through the radiator core support so air is forced to go OVER the truck, not into the engine compartment or under the truck;

 

SERIOUS (mileage savers but performance killers) -

11) install a mileage/economy optimized camshaft;

12) install tighter rear gears (change your 4.10s for 3.73s or even lower)

13) go back to stock-width or narrower tires (rolling resistance)

 

MILEAGE KILLERS -

* Drop kit that changes the instant center of your rear suspension (it's less efficient)

* Shorter tires (I went from 32" to 30" diameter and it cost me .5-mpg)

 

And that's what I can think of off the top of my head.

 

Installing a CAI and catback does help WOT performance, but I am not aware of anybody that's actually gained cruise mpg by swapping CAI, catback, or installing headers. And remember that the point here is to save money, it makes little sense to put $5K to $10K in the truck to save $2000 in gasoline over the next few years; for that reason a lot of us are buying cheap used daily driver economy cars that are also cheap to run and insure, plus with a multi-car discount the insurance company just might let you put your truck on a "sunny day only" insurance policy and save you hundreds there as well (tell them, "it's a Corvette with a bed!") I've seen the light with the beater cars, they pay for themselves in a couple years.

 

Mr. P.

Edited June 18, 2008 by Mr. P. (see edit history)

[Champion201]

9) have belly pans made for under the truck, this is as big a mpg help as the tonneau cover;

10) aerodynamically close all leaks through the radiator core support so air is forced to go OVER the truck, not into the engine compartment or under the truck;

 

Mr. P.

 

You Steve, could you please elaborate a little on these 2 items?

 

Thanks Bud,

 

Mike

[NTMD8R_SS]

Im about to remove all unnessesary item (to me) like the hitch and spare and a few misc. items.

[Hankg42]

Be careful what you deem unnecessary. On Saturday, some debris in the road cut the sidewall of a tire with less than 7500 miles on it. Without my spare, I would have had to call for a flatbed. I can't see the weight of a spare being worth that.

[misterp]

Be careful what you deem unnecessary. On Saturday, some debris in the road cut the sidewall of a tire with less than 7500 miles on it. Without my spare, I would have had to call for a flatbed. I can't see the weight of a spare being worth that.

Sorry good point, I got rid of mine because of the Baer brakes, my spare won't fit so I got rid of it. Around here the worst tire hazards are fresh roadkill; I think the last time I carried a spare was back in the 80's But you're right there's nothing fun about being stranded.

 

Mr. P.

[Hankg42]

Sorry good point, I got rid of mine because of the Baer brakes, my spare won't fit so I got rid of it. Around here the worst tire hazards are fresh roadkill; I think the last time I carried a spare was back in the 80's But you're right there's nothing fun about being stranded.

 

Mr. P.

I guess I actually added weight... I bought an additional stock 20" rim because of my Baer brakes. I'm glad I did!

[Champion201]

Sorry good point, I got rid of mine because of the Baer brakes, my spare won't fit so I got rid of it. Around here the worst tire hazards are fresh roadkill; I think the last time I carried a spare was back in the 80's But you're right there's nothing fun about being stranded.

 

Mr. P.

 

Like you stated earlier, get a AAA card.

[misterp]

You Steve, could you please elaborate a little on these 2 items?

 

Thanks Bud,

 

Mike

Take a look at a Corvette, I mean a real look. Even better, take a look at a Ferarri 599. The floorpans are FLAT, the wheelwells are totally enclosed and on the 599 they're vented as well. On the 599 the bottom of the engine bay is totally enclosed with louvres to extract radiator heat from the engine compartment.

 

Ever wonder why the Silverado hood acts like it's trying to fly off it's hinges above 110-mph? It's because the wind rush penetrates the entire front grill and the first solid object that wind meets is the firewall/floorboard, which directs a lot of the wind up (to blow the hood off) as well as rush down the firewall and drag all along the underbody of the truck. In fact the whole engine compartment becomes pressurized at speed with all this air to the point it blocks the fresh air from going through the radiator! With our EFan Kit, the truck runs at 175 in the dead of summer heat driving like a pissed-off teenager in city traffic, but when you get on the freeway at 70-mph under cruise control (low load) the temp needle climbs straight to 200-degrees at parks there, because there is so much pressurized air underhood behind the radiator it impedes fresh airflow traveling through the cooling fins. The answer here is to do exactly what Dodge did on the SRT-10 truck, at your next car show take a hard look behind the front grill of that truck and you'll see a bunch of tinwork in place not found on other Ram trucks, not only does it force air through the radiator correctly but it lowered the Cd on that truck a ton, like from .42 (or so?) down to .35-ish.

 

The ideal solution to the underhood air problem IMO is to do exactly what Saleen did on the 337 truck - first make the grille/radiator core support totally wind-proof, then provide an extraction vent on the HOOD so hot radiator air is sucked out the top of the hood and OVER the truck, not allowed to go under the truck and drag along the bottom. I've sketched several "perfect" hoods, if I made a hood I would have a cowl hood (like the Goodmark) and *also* add an extractor vent just behind the radiator core support (like a Ford GT/GT40). Somebody makes a road racing hood like this for the C5 Vette crowd, I forget exactly who...

 

Belly Pans: crawl under your truck, under the cab and take a look at the foot-wide gap between the exterior painted skin and the frame rail - if you take a sheet of thin material and cover this open area from the back of the front wheel-wells to the front of the back wheel-wells you will gain 1/2-mpg, this is not my guess but rather a little published fact from GM's truck aerodynamics team. If you look at the same area under a Corvette/Ferarri you will notice this is exactly what they've done to thir underbody's too.

 

Another chief offender is the rear bumper, it's hanging there like a parachute; I want to box-in the underside of the bed, from the rear of the axle to the underside of the bumper/rollpan.

 

The trick of all this aero stuff is to do it in a way where you are not adding 100+ pounds of material to the truck. My truck goes great to about 90-mph and you can just feel the aero problems exact their toll. Down the road I want to do some of these ideas, the goal being improved efficiency without hurting my 1/4-mile time. I've got some other ideas too

 

Mr. P.

Edited June 18, 2008 by Mr. P. (see edit history)

[Champion201]

Thanks P.

 

Now I cant wait to get off work to go crawl under the truck and see how difficult it will be to have some stuff fabbed up, I have a buddy that works in a metal shop.

 

BTW, does P stand for Petrosexual?

 

 

 

 

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