LS-ONE_DAY

All you A4 guys, I've been trying to find a thread that lists observed mpg without much luck. Basically I want as much info as I can get to figure out how much I can expect to lose putting a bigger cam in my car. I'd like as much input of ya'lls experience as possible so we can gather it all here for those economically minded folks.

For cam only -

Year:
Gear Ratio:
Any mods other than cam (bolt ons, trans, converter, rear):
Weight:
Type of driving (in % maybe):
Mpg before cam (city / highway / combined):
Cam (with specs):
Observed mpg (city / highway / combined):

For H/C, same thing but include whatever the type of heads are.

thunderstruck507

iTrader: (18)

Year: 1971 Chevelle
Gear Ratio: 3.42 with 26" tire
Any mods other than cam: Yank 3600, 12 bolt, full bolt ons
Weight: ~3800 street with driver
Cam (with specs): EPS 230/238 .615/.600 113+2
Heads: GM 799, mild hand port on intake side, sandpaper rolls only on exhaust, milled .010", stock head gasket
Observed mpg (city / highway / combined): average of ~18.5 mpg highway, high of 21mpg on 3 hour all interstate road trip

arock24

iTrader: (4)

Year: 2002
Gear Ratio: 3.23
Any mods other than cam (bolt ons, trans, converter, rear): 243 heads (hand ported), lt/ORY, lid, 3600 converter (rest in sig)
Weight: ~3600
Type of driving (in % maybe): 70% city/30% highway
Mpg before cam (city / highway / combined): 18/22/20
Cam (with specs): 231/234 .641/.598 111 lsa (very close if not exact)
Observed mpg (city / highway / combined): 16/20/18 (base tune)

*numbers based on "spirited" driving

PREDATOR-Z

gay thread

OutrunNAScaR14

iTrader: (4)

Year:2001
Gear Ratio:3.23
Any mods other than cam (bolt ons, trans, converter, rear):3200 stall, ls6 intake, headers, ported tb, 853 heads
Weight:3800
Type of driving (in % maybe):daily driver
Mpg before cam (city / highway / combined):NA
Cam (with specs):235/234 .604/.598 112 lsa
Observed mpg (city / highway / combined):14 mpg highway

88Fbody6L

iTrader: (5)

Then don't offer your ignorant comments

96capricemgr

iTrader: (1)

Not an LS but with my Caprice toy sedan vs wagon I get 3mpg or so less with the hotrod vs the bone stock car. Now granted the stock wagon is heavier, but the sedan has 3800stall 4.10s cam on a 108 LSA for a lot more overlap than LS guys generally run. I get very high teens out of the sedan in mixed driving or highway to the track then racing and highway home. Never checked specific highway without the racing in the middle. Raceweight in 41-4200lbs so street weight with slicks and such in trunk probably 150-200lbs more because the rear street tires/rims are 60lbs apiece, plus jack tools etc.

Again I know it is not an LS f-body but I think it still makes the point that HP doesn't have to affect fuel economy that much, now if you make a habit of using all the extra HP all the time that is another story.

PREDATOR-Z

Why are you offended?

96capricemgr

iTrader: (1)

I can see the point, the modifications are going to cost way more than the increased fuel consumption. Hell I bet just the price of a set of valvesprings every 15K miles or so will be more than the fuel consumption change.

I can see not getting reckless about fuel economy with your "hotrod" but to really hurt economy you would need something silly like non-lockup converter or an out of the box carburetor in place of the injection, or big engine mods with stock tuning, something really dumb like those things.

88Fbody6L

iTrader: (5)

I'm not personally offended, but its irritating to see someone post a question and others comment about how stupid the question is. Nobody asked what people thought of the thread. The OP had a legitimate question and you posted nothing to contribute.

PREDATOR-Z

It is still gay. Want economy, get a Jap shoebox.

ls1 1990 VN

PRED is right.

If you want economy, stick with the standard cam, add bolt-ons, get it tuned,
then the big fail safe...Fit a restriction block under the accelerator pedal.

wildcamaro

iTrader: (15)

H/c/I a4 3.73....15 mpg and hoping it decreases with my ET in the future

prokilllsx

H/C 3.90 gears 3,200 stall headers pulley avg's 19mpg on a SD tune with some spirited driving every time she hits the road. Should hit 22 to 24 on a relaxed (60 mph) road trip.

If you can afford to mod you can afford to fill.

99Bluz28

iTrader: (35)

Don't forget tire pressure, it play's an important part in fuel economy to.

96capricemgr

iTrader: (1)

That is a good point and also reminds of the fact that when we put new tires on the wife's car I did not pay attention to LRR tires and lost a solid 10%. So tire design and pressure play a roll.

JakeFusion

iTrader: (7)

Stickier wider tires hurt fuel economy more than anything else.

I lost 5mpg on my Jap shoebox going with really sticky Yokohama tires that were 30mm wider all the way around. That was the only change.

In a month or two I'll let you know how a big *** stall and h/c affect my T/A.

96capricemgr

iTrader: (1)

On my wife's 03 Impala we went from the stock suck at everything Tigerpaws to Goodyear Assurance Triple Tread in the same size and lost 10% fuel economy. Certainly wider softer rubber hurts but even staying with the same size a LRR vs a standard tire does make a difference. The Goodyears while they hurt MPG drastically improved grip in all conditions so the MPG hit was worth it safety wise.

JakeFusion

iTrader: (7)

I agree. I don't skimp on tires. Ever. They are the most important aspect of performance and safety.

Detoxx03

iTrader: (14)

Year: 2002
Gear Ratio: 3.23
Any mods other than cam (bolt ons, trans, converter, rear): full exhaust, fast 92 intake and tb, and yank ss3600
Weight: 3600
Type of driving (in % maybe): 50/50
Mpg before cam (city / highway / combined): 23
Cam (with specs): 228/230 from Futral Motorsports
Observed mpg (city / highway / combined): 19