[Vettezuki]

Originally Posted by joedls

I doubt if his dyno sheet starts low enough to have a reading at 1100-1200 RPM.

Yeah, after posting I checked mine, no dice. But we might be able to infer by starting torque around 2,500rpm. I bet you his is at least 100ft lbs, more than my H&C NA LSx.

[enkeivette]

Originally Posted by enkeivette

My Vette gets best gas mileage at about 90 mph, my Neon... probably 55 mph.

Don't know why you guys keep posting that "most cars will do better at 55mph" like you're trying to prove a point to me. In the very first post, I said that my Neon will do better at 55. I'm sure most of the Honda Civics and Nissan Sentras out there could gain a mpg or two by slowing down their speed on the freeway.

Originally Posted by enkeivette

And I will stand by my opinion that most V8 cars and trucks (with modern OD transmissions) will get better mileage going faster than 55mph. ...And those V8 cars are the ones that are wasting all the gas! We should be gearing economy commericals towards them.

My point was, and is, that most of the bigger more powerful cars and trucks out there... you know, the one's sucking all the gas, will not do better at 55 mph. See above.

1177 is high idle speed. No motor will move a car along at that rpm without lugging. Don't know what else to say. I can explain it to ya, but I can't understand it for ya.

[enkeivette]

Originally Posted by Vettezuki

MOST cars 55mph = Better Mileage than 75 mph, no question.

My Vette would NOT be happy cruising at 1,200rpm in 6th PERIOD . It would be lugging . . . PERIOD, which ain't so good for wear and tear. You have a 500+HP Super Charged motor. Guess what? You're making tons of torque at that RPM and therefore have plenty of power. Post your dyno sheet.

And I had 521 hp with a leaking intake manifold gasket (2 ports) and a leaking head gasket (2 cylinders) with a 15:1 AF ratio at only 5lbs of boost.

Prob made a lil more with 9lbs of boost all sealed up with jets 10-12 sizes bigger in the carb.

[SeanPlunk]

Originally Posted by enkeivette

My point was, and is, that most of the bigger more powerful cars and trucks out there... you know, the one's sucking all the gas, will not do better at 55 mph. See above.

1177 is high idle speed. No motor will move a car along at that rpm without lugging. Don't know what else to say. I can explain it to ya, but I can't understand it for ya.

Yeah, you are WRONG. I don't care what you say. If you want me to post this on other boards to prove you wrong, I'll be happy to do it. A Yukon, Avalanche, whatever, will do better cruising in OD at 55mph than it will at higher speeds. You are wrong about lugging. The Camaro could quite happily hang at that RPM WHILE CRUISING ALONG AT 55MPH!!! The Cobra will too. I just consulted my friend with a 4.6 2V F150 and he says his will too and won't lug. Why is this so hard for you to understand?

[Vettezuki]

All further arguments are pointless. Each person who is suffeciently interested should do a 100 mile test loop at 55 and whatever speed they think will yield best mpg, log their OBSERVED mpg and report. No speculating.

My hypothesis is that *my* Vette will get its best mileage around 70-75mph but my GMC Sierra 1500 would get its best around 55-60.

[enkeivette]

Originally Posted by SeanPlunk

Yeah, you are WRONG. I don't care what you say. If you want me to post this on other boards to prove you wrong, I'll be happy to do it. A Yukon, Avalanche, whatever, will do better cruising in OD at 55mph than it will at higher speeds. You are wrong about lugging. The Camaro could quite happily hang at that RPM WHILE CRUISING ALONG AT 55MPH!!! The Cobra will too. I just consulted my friend with a 4.6 2V F150 and he says his will too and won't lug. Why is this so hard for you to understand?

Looks like I can reuse this response.

Originally Posted by enkeivette

Good argument Sean.

...If anyone disagrees with my understanding of the conditions that yield the best mpg, please explain why and provide your own set of conditions. Not going to play "No it's not!" "Yes it is!" Thaaat gets old.

Sean, does your friend with the NA F150 happen to have a vacuum guage in the cab? Didn't think so. So how does he know whether or not he's lugging.

And why would I be swayed by the opinions of a bunch of forum sh*t talkers that have less hands on experience than I do? You could get all of LS1forum to disagree with me, I don't expect to learn anything from a bunch of checkbook tuners.

I miss you Sean.

Not talking about hardcore lugging here. Not talking about the sort of lugging that causes a deep deep tone and the catalytic converters to rattle. This is about the very tipping point where you might be getting 17" of vacuum at 55mph but 20" of vacuum at 65mph. Not everyone can feel that slight difference with their foot. I'm talking about the kind of lugging that I do everyday in my Neon because I'm used to driving a V8. And you need to consider the average rpm and vacuum at the same time. If the car does fine at 55 cruising but lugs SLIGHTLY up a grade, then you need to take that into account, maybe the car would do better at 65 at the same vacuum level because the vacuum will remain constant up a slight grade at a higher speed. You need to take into account whether the car is downshifting. This is an average, where will cars get the best average? To be honest, I don't know. Neither do you, neither does LS1forum. But if I had to bet... I'd bet a lot of money that it's not at 1177 rpm in a Vette or a Cobra. And I bet some money that it's not at 1445 rpm in a truck... AVERAGE.

I'd go make a video of this slight difference in my car, but you already casted my car out as some freak exception. So I don't know what else I can do for you.

[SeanPlunk]

Originally Posted by enkeivette

Looks like I can reuse this response.



Sean, does your friend with the NA F150 happen to have a vacuum guage in the cab? Didn't think so. So how does he know whether or not he's lugging.

And why would I be swayed by the opinions of a bunch of forum sh*t talkers that have less hands on experience than I do? You could get all of LS1forum to disagree with me, I don't expect to learn anything from a bunch of checkbook tuners.

I miss you Sean.

Not talking about hardcore lugging here. Not talking about the sort of lugging that causes a deep deep tone and the catalytic converters to rattle. This is about the very tipping point where you might be getting 17" of vacuum at 55mph but 20" of vacuum at 65mph. Not everyone can feel that slight difference with their foot. I'm talking about the kind of lugging that I do everyday in my Neon because I'm used to driving a V8. And you need to consider the average rpm and vacuum at the same time. If the car does fine at 55 cruising but lugs SLIGHTLY up a grade, then you need to take that into account, maybe the car would do better at 65 at the same vacuum level because the vacuum will remain constant up a slight grade at a higher speed. You need to take into account whether the car is downshifting. This is an average, where will cars get the best average? To be honest, I don't know. Neither do you, neither does LS1forum. But if I had to bet... I'd bet a lot of money that it's not at 1177 rpm in a Vette or a Cobra. And I bet some money that it's not at 1445 rpm in a truck... AVERAGE.

I'd go make a video of this slight difference in my car, but you already casted my car out as some freak exception. So I don't know what else I can do for you.

Spin it however you want, the fact remains that on a normal highway in the United States, the average vehicle will get better mileage going 55mph than faster. That includes your dad's Avalanche. Any vacuum difference would be negated by the higher air resistance in your scenario. Going on a flat road cruising, the Cobra will do just fine at 1200rpm's and burn less gas than if I was going faster. Less fuel is being mixed, less air resistance, etc. I posted this on another board, we'll see what they say. Personally I don't know why you're still arguing about this because you're just wrong

[SeanPlunk]

HAHA, here is the link to the LS2 thread: http://www.ls2.com/forums/showthread...hreadid=651842

The first response sums up my thoughts on what you're saying exactly.

[enkeivette]

Omg Sean, you're wrong. You're wrong. You're wrong. You're wrong. There, no I've said it more times. Do I sound more credible?

First of all, you skewed what I said originally. I never said that MOST vehicles will do better at 55mph. I said the commercial claiming that you will get better mpg at 55mph (an absolute statement) was BS. Remember the BS flag? Now I'm just repeating myself, which is why I'm so bored of this. Secondly you made me sound like a jackass, "he thinks he gets best mpg at 90 mph." Do they know that this is a blown 600hp motor with a race carb, low gearing and an OD trans that was never made for the car? Did you tell them that my car is gear limited to 270mph?! If you were so confident, why didn't you just copy and paste my original post?

As far as the responses on LS2forum, chocolate chip cookies and he's retarded with lots of smiley faces. You see, this is why as I said earlier I realy don't give a flying f*ck what checkbook tuners (like yourself) have to say. I can't even believe that you sent me that link, how embarrassing for you.

Throughout this entire argument, you have NEVER provided your own formula for determining best mpg, or even given me any technical reasoning as to why mine is wrong. You just keep saying "you're wrong Adam!" Like, seriously? Are you 12? I will not respond again until you provide some sort of techincal argument of your own as to why you think that I'm wrong. I feel like I'm arguing with a missionary. "No these people don't have vacuum guages, but you just gotta have faith Adam."

I'm arguing with someone who has no hands on experience, no applicational knowledge. How many motors have you tuned? How many motors have you built in your garage? How many superchargers and turbos have you installed? How many people have paid you to do work on their cars? But you want to argue with me about engine dynamics? Without even a techincal argument or a decent sense of reasoning as to why my argument is flawed. Step away from the keyboard, pick up a wrench Sean, you might learn something.

I told my Mercedes tech friend (UTI graduate) that you said you think a C6 can cruise at 1177rpm without lugging, and he laughed. But no... he doesn't have an LS2forum account, so I don't know what that will be worth to you.

And oh yeah, VACUUM READINGS TAKE AIR RESISTANCE INTO ACCOUNT. THE MORE AIR RESISTANCE, THE HARDER THE MOTOR WILL BE FORCED TO WORK TO MAINTAIN SPEED AND THEREFORE THE LOWER THE VACUUM WILL BE. Thought maybe if I typed it in caps that time you'd catch on.

[SeanPlunk]

I did post a link to the entire thread. I just gave them a summary. Also, you did state your car would get it's best mileage at 90mph which is completely laughable(or crazy and stupid if you prefer). I posted your original post so you won't be so butthurt. It doesn't make you any less wrong. My contention the entire time has been that the AVERAGE vehicle will get better mileage going 55mph cruising than at higher speeds. You have done nothing to refute that. I didn't say it was some magic MPH, but it will net you better mileage than higher speeds for MOST vehicles. I don't care what your Mercedes Tech friend said or what you say. You may know how to work on cars, but I don't give a shit. Every car I've ever driven could cruise just fine in OD at 55 including Civics, Accords, Cobalts, Aveos, Focus', etc.