Assume something like a 220/224 cam in a 6.0L. 10 to 1 c/r with all the bolt ons. What would be the differences in MPG between that cam with a 112 LSA and the same cam with a 115 LSA? Highway cruising at 2000 rpm. Guess you'll have to assume an optimum tune for each cam. I understand the effects of different LSA's on idle, power band, etc. Your thoughts appreciated.

 

Anyone care to weigh in on this one?

 

I get 16-17 mixed 50/50 city/highway. Mine is a lq9 with 243 heads soooo roughly 10.8:1. My cam is listed in my sig

 

I get 15-16 mostly city with my 218/222 .544 113lsa in my lq4 with stock 317s

 

The cam will cost you 1-2 mpg. Trying to figure out mileage between a 115 lsa and 112 lsa is ridiculous in my opinion, and complicated by the fact that most comp cams aren't usually ground exactly correct anyways.

 

Ridiculous? Not to me. I'll put 30 to 40K miles a year on this rig. Operating characteristics are very different when comparing wide and narrow LSA's on otherwise indentical cams.

 

Do you just make stuff up so you have something to post? A cam is not going to lose you mpg if it is tuned correctly. Also where is the proof about comp not grind cams correctly.

 

To actually answer your question, its overlap that you should reduce in order to maximize fuel economy.

In this case, since both cams have the same intake and exhaust durations, you can say that a "larger" LSA will have less overlap and will theoretically get better mileage.

 

My truck went from 20mpg highway to 18-19 as it sits rt now.. I don't feel like I lost much.. 5.3 stock with 3.42 to 5.3 10.5:1 compression LT headers 4.10s 30" tire 222/226 111+2 lsa cam and 3600 stall... I don't c u loosing MPG with a 111-115 lsa cam.. only reason I might have lost MPG is because I went from 3.42 32" tire spinning 1700@70 to 4.10 with a 30" tire spinning 2300@70 but not because of my cam

 

A stall is what usually chugs the gas