Best cruising speed for highest MPG.

[ArgentoAtl]

Originally Posted by FRiSson

Its from the article. I did not invent the idea. I assume PM did some testing to confirm the half-maximum rule. I do suspect that not all fuel systems respond the same - so results will vary. In particular, the twins have a very complex fueling system that involves both port and direct injection being involved at times, and not in a simple linear speed order. As far as going with the MPG sensor, that is an imprecise device. I am not saying it is necessarily wrong, but that it isn't sufficient evidence to go on.

Thanks for your direct reply.

My interest in economy is for in-town driving because I believe I can figure out how to drive in high gear economically. So the rule of thumb you referenced is very relevant. Now that I have confirmed your reference (see below*), how do I accomplish it? For example what is the 0-60 minimum time for an FRS and what are the shift points to achieve that minimum time? Right now I am shifting quite early so that I am in 5th gear at about 40mph and am getting 25mpg. 45 is my cruising speed around my area of town most of the time. Does this sound about right for reasonable economy around town?

Thanks, again

Brian in Atlanta



* I see now that I read a more recent article than the one to which you are referring. You were quoting the following.

http://www.popularmechanics.com/cars...ummer-8922590/

[FRiSson]

Originally Posted by ArgentoAtl

Thanks for your direct reply.

My interest in economy is for in-town driving because I believe I can figure out how to drive in high gear economically. So the rule of thumb you referenced is very relevant. Now that I have confirmed your reference (see below*), how do I accomplish it? For example what is the 0-60 minimum time for an FRS and what are the shift points to achieve that minimum time? Right now I am shifting quite early so that I am in 5th gear at about 40mph and am getting 25mpg. 45 is my cruising speed around my area of town most of the time. Does this sound about right for reasonable economy around town?

Thanks, again

Brian in Atlanta

* I see now that I read a more recent article than the one to which you are referring. You were quoting the following.

http://www.popularmechanics.com/cars...ummer-8922590/

It is really hard to evaluate your driving. How much traffic and how many stops you make. I would say that if you face moderate traffic and have to stop or slow every half mile or slow (typical retail strip), 25mpg is reasonable. However, if it is a mix of non-stop highways and a handful of short streets with stop signs, or long suburban roads without a lot of stops, you should do a little better. On the other hand, if you use air conditioning a lot (Atlanta) and if you no longer have the high efficiency Michelin Primacy tires, that will drop your mileage a couple of mpg. The rule of thumb is higher engine revolutions equals more fuel consumption in a typical gas motor. What I don't know is when revs become so low that you lose efficiency. I have driven several 4-cylinder automatics that drop as low as 1,400 rpm on streets and highway. But driving a manual in those rev ranges is downright unpleasant and certainly unresponsive. I wouldn't recommend it. Highway cruising at 1,800rpm ( I think that is about 50mph in 6th) would be okay - but not much fun. In terms of biggest bang for your fuel buck (I assume you are already driving reasonably). The best MPG return on your investment would be to buy high-mpg tires, or to buy an automatic. The auto gets you a much lower axle ratio. If I was a tuner, I would look to buying an overdrive like I once had in a Volvo. It was a Laycock unit that attached to the end of the transmission. When you flicked the switch it would lower your revs about 20% in any gear. That's okay on the highway. At flat cruising speed your car only needs a tiny fraction of the engine's power to maintain speed.

[wired]

35mpg. I lol'd.

I've driven 1300 miles so far. The first 1000 miles I averaged at about 24mpg (mixed streets/highway), usually -but not always :p- shifting between 3-4k rpm, trying not to accelerate too fast.

The last tank gave me a bit less than 22mpg - but it included some spirited mountain driving. Still much better than what my RX-8 used to do. Similar driving with that car would probably get me around 15mpg

I doubt I'll ever have the patience to get close to even 30mpg. But I have a trip to LA coming up in about a month, who knows

[shiro]

Lol, it's hard to say. I think the best I've gotten on a tank (back in the days of old and non-modified) was 333-350 miles on a tank before I had the "E" light. But now burning corn fuel and my lead foot I get about 120-200 miles on a tank :P.. 450whp @21psi and got to love it when your "current mpg" reads 2mpg on WOT with 1000cc injectors :P...

BUT for sh*ts and grins I'd do to main comparisons for highway: Speed/Distance & Time/Distance.
1. 70 mph for distance with best mpg (highway)
2. 78-80 mph for time with best mpg (highway)

[Kaotic Lazagna]

If traffic and the amount of lanes permits (and as long as the speed limit isn't over 65), I would say 50 mph will yield you the best mpg (be prepared to piss off a lot of people tho). If not, then either 55 mph or 60 mph.

I can't do 50 mph anymore, but back when I used to be able to, best mpg I got was 41.4 mpg. Now, slowest I can possibly go is 55 mph, but then again, half my week I'm stuck in traffic. So now I'm averaging 34 to 36 mpg. All of these are calculated mpg, not from the generous OEM gauge.

[NOHOME]

Buy a Prius.

[Dadhawk]

Originally Posted by NOHOME

Buy a Prius.

Compared to the other cars I would have purchased instead, the 86 is my Prius, and I have told people that. It gets about twice the mileage of any other car I would considered owning as a DD.

Not to pick on you @NOHOME but I'm not sure I understand why its not possible to enjoy a sports car and be concerned with its fuel usage. They are not mutually exclusive. I track MPG as a measurement of "health". The fact that I average over 32MPG in almost 60K miles of driving is amazing to me. I would have never expected that, particularly given I in no form, manner shape or function come close to a hypermiler (if that's the right term).

Mind you, I don't race it on a track every day, or sit in city traffic, which I would expect to drag it down, but I am always the first off the light (sorry for the disbelievers but I've never been beaten by a soccer mom in a minivan) and consider every "Caution 25MPH Curve Ahead" sign as a challenge to better than double it.

[Tcoat]

Originally Posted by Dadhawk

Compared to the other cars I would have purchased instead, the 86 is my Prius, and I have told people that. It gets about twice the mileage of any other car I would considered owning as a DD.

Not to pick on you @NOHOME but I'm not sure I understand why its not possible to enjoy a sports car and be concerned with its fuel usage. They are not mutually exclusive. I track MPG as a measurement of "health". The fact that I average over 32MPG in almost 60K miles of driving is amazing to me. I would have never expected that, particularly given I in no form, manner shape or function come close to a hypermiler (if that's the right term).

Mind you, I don't race it on a track every day, or sit in city traffic, which I would expect to drag it down, but I am always the first off the light (sorry for the disbelievers but I've never been beaten by a soccer mom in a minivan) and consider every "Caution 25MPH Curve Ahead" sign as a challenge to better than double it.

Me too. Word for word, in every single detail!

[Bergen23]

Originally Posted by Dadhawk

Compared to the other cars I would have purchased instead, the 86 is my Prius, and I have told people that. It gets about twice the mileage of any other car I would considered owning as a DD.

Not to pick on you @NOHOME but I'm not sure I understand why its not possible to enjoy a sports car and be concerned with its fuel usage. They are not mutually exclusive. I track MPG as a measurement of "health". The fact that I average over 32MPG in almost 60K miles of driving is amazing to me. I would have never expected that, particularly given I in no form, manner shape or function come close to a hypermiler (if that's the right term).

Mind you, I don't race it on a track every day, or sit in city traffic, which I would expect to drag it down, but I am always the first off the light (sorry for the disbelievers but I've never been beaten by a soccer mom in a minivan) and consider every "Caution 25MPH Curve Ahead" sign as a challenge to better than double it.

I've been averaging between 7.4 and 9.9 l/100km. In fairness, a lot of my driving is highway, but it includes stop and go as well as city. On the highway, I do about 110kmh, so, that's around 67mph?

[Tcoat]

Originally Posted by Bergen23

On the highway, I do about 110kmh, so, that's around 67mph?

If you want to spot me on the highway you are going to have to keep your eyes open because at 110 I am just going to be an orange flash as I pass you (cursing at the "old lady" drivers all the while)!

[Bergen23]

Originally Posted by Tcoat

If you want to spot me on the highway you are going to have to keep your eyes open because at 110 I am just going to be an orange flash as I pass you (cursing at the "old lady" drivers all the while)!

Gas is expensive, and I'm cheap. Plus my car is an absolute cop magnet right now. Gotta give them no excuse to pull over a young guy in a low, loud car.

[Tcoat]

Originally Posted by Bergen23

Gas is expensive, and I'm cheap. Plus my car is an absolute cop magnet right now. Gotta give them no excuse to pull over a young guy in a low, loud car.

Ya, I hear you! See I am not so worried about my low(ish), loud(ish) car since as soon as they see me they tend to just go away. May push my luck to far one day though but I will deal with that if it happens. Besides 98% of my time is spent in the wide open stretch's of the 401 where if you are doing under 125 people will be on your ass.

[Bergen23]

Originally Posted by Tcoat

Ya, I hear you! See I am not so worried about my low(ish), loud(ish) car since as soon as they see me they tend to just go away. May push my luck to far one day though but I will deal with that if it happens. Besides 98% of my time is spent in the wide open stretch's of the 401 where if you are doing under 125 people will be on your ass.

401 guelph to Toronto, 125 does not exist.

[Tcoat]

Originally Posted by Bergen23

401 guelph to Toronto, 125 does not exist.

Lucky to do 25 on that stretch some days.