cam affecting gas mileage

[02gmcbandit]

ok guys i was thinking and im wondering how the cam i got is gona affect my gas mileage?? its a 226/229 cam on 112 LSA. right now as my truck sits i get 24 mpg at 60mph with cruise control on hwy ( if i did my calculating right after my trip yesterday, went 145.3 miles on a quarter of a tank). not sure about town cause i cant help but get in it every now and then haha.

any help and insight would be greatly appreciated.

[zeake]

Not sure how much but cams always affect milage.

[Show&Go]

Do you have a cam in it now and swapping to larger? I still get close to 20 on cruise at 60 but my cam is a good bit smaller...

[skeet]

what else do you have to support that cam?

when you start changing internal parts in any engine it will always affect the gas mileage, specially if you dont have the rest of the supporting mods.

take my setup for instance, i can tune it down to gain better gas mileage then change the tune for the track!!! but personally gas mileage is the lease of my worries

[02gmcbandit]

right now i dont have many mods, just full exhaust from manifolds back, volant ram air intake, 4.11 gears, built 4l65e with transgo hd2 shiftkit vette servo, and tune. geting LT's, and bigger injectors before cam install and also a circle d torque conv.

[pl4yboy]

The stall is going to hurt mileage a little.

[Show&Go]

My mileage dropped about 2 digits when I put in a stall. I dont know if its typical but expect that at least

[txarkitekt]

Ok--first things first... Since you do not have an 03+ truck, DO NOT base your mpgs off the needle gauge on your dash. Not accurate. BUT--I am not saying that I don't believe you...

The best thing to do--Fill your tank completely. Then drive your route and clock your mileage. Go back to the gas station and fill up completely again--then look and see how many gallons it took to fill your tank--this is the amount in gallons you used on your drive. From there, do the math of miles traveled versus gallons used.

[pl4yboy]

Ok--first things first... Since you do not have an 03+ truck, DO NOT base your mpgs off the needle gauge on your dash. Not accurate. BUT--I am not saying that I don't believe you...

The best thing to do--Fill your tank completely. Then drive your route and clock your mileage. Go back to the gas station and fill up completely again--then look and see how many gallons it took to fill your tank--this is the amount in gallons you used on your drive. From there, do the math of miles traveled versus gallons used.

I wouldn't say that any gauge is very accurate. I know I can drive 250 miles on the first half tank, and 150 on the second half.

[txarkitekt]

I wouldn't say that any gauge is very accurate. I know I can drive 250 miles on the first half tank, and 150 on the second half.

Hence the reason why I said to base your fuel volume on the gas pump's digital readout versus the gauge on the dash.

But to get back to the point of this thread--YES, the cam will effect your mileage. It will require extra fuel at most points along the RPM range. And since you will be running a Circle D converter, that will hurt your city mpgs. A live tune will be best to get the most out of your cam and supporting mods, plus it will get you the best mpgs.

I am not saying your mpgs will go down horribly, but they will be less since you will have more mods and a heavier right foot to take advantage of those mods. Your hwy mpgs will be affected the least--it might not even change--but if it does, 1-2 mpgs maybe.