Squeezing a few more mpg out of a mustang gt

[gk_ghig14]

I was trying to do like mcrews did to where you can't really see the block. I may give it another shot tomorrow and see if I can get it to work

But tonight I drove around town(against my better judgement) and my average mpg went from 17 after I filled up this afternoon, to 24 with a mix of 75% city and 25% highway. If only I could maintain that during the week I'd be ecstatic

Also according to my dashcmd app(similar to torque) it's saying my Vaccuum never went above -15 tonight

[gk_ghig14]

This may be a vehicle specific question, but how much load should I try to keep my car around(yes I read the DWL tip)? I'm guessing as close to 0% as possible or to where my vacuum is at around -25 on the gauge?

[UltArc]

When in my Mustang, I drive w/ 30 MPG load until I hit target speed, capping at 57-59, then cruise control unless another variable changes that.

Insight is 80% load to 57-59 mph, if the speed limit is higher I will drive as fast as I can while still exceeding 75 mpg.

[gk_ghig14]

Got oh so close to 20 mpg on this last tank, 19.8. If my friend hadn't come into town for a weekend, I'm sure I could've hit over 20. Hopefully I can hit 20 this tank

Talked to my tuner about changing the 6th gear minimum speed from 43ish to around 35 but he said that would lug the engine :/ But I have free time this week so I'm going to try to get the grille block done in hopes of breaking 20 mpg commute tank

[digital rules]

Originally Posted by gk_ghig14

Talked to my tuner about changing the 6th gear minimum speed from 43ish to around 35 but he said that would lug the engine

Only you will know if the engine is actually lugging. Try 35-40 & listen to the engine. You should easily be able to tell what is the minimum speed for the top gear.

[UltArc]

Bull crap to your tuner. A couple of people at Mustang Evolution have said similar things, but my 3.7 holds 6th as low as 26 mph with low engine load (~40%), and I have a very hard time believing your two extra cylinders and 100+ ft/lb torque can't handle it.

Don't get me wrong, jumping on the throttle doesn't do much but put strain on the engine, but for just cruising or suddle acceleration (25 zone to 35, 35 to 45, so on).

[serialk11r]

I've never seen anyone get a professional tune like this, but since all new cars are throttle by wire, what you could do is have 18:1 AFR say above 1500rpm and below 50% load, increase the throttle opening accordingly, and then make it jump straight to stoichiometric above 50% load and at idle and such. That way you never accidentally run 15-16 AFRs and damage things. It would be difficult to get the lean to stoich transition smooth but it would be worth the fuel economy benefit I think, especially on a large motor like that.

With my primitive cable throttle if I were to get a standalone and try to tune it, I would have to have it transition back to stoichiometric at a lower load to avoid accidentally destroying the engine.

[gk_ghig14]

Originally Posted by digital rules

Only you will know if the engine is actually lugging. Try 35-40 & listen to the engine. You should easily be able to tell what is the minimum speed for the top gear.

I already know it's 43ish cause my car has a manual mode and no matter how many times I press the upshift button before that, it won't do it

Originally Posted by UltArc

Bull crap to your tuner. A couple of people at Mustang Evolution have said similar things, but my 3.7 holds 6th as low as 26 mph with low engine load (~40%), and I have a very hard time believing your two extra cylinders and 100+ ft/lb torque can't handle it.

Don't get me wrong, jumping on the throttle doesn't do much but put strain on the engine, but for just cruising or suddle acceleration (25 zone to 35, 35 to 45, so on).

Auto or manual 3.7?

But I agree something is weird, if I can start in 3rd gear from a stop why can't I be in 6th gear super early?

[UltArc]

WHAT?!

Standard. C'mon son. (Psych reference, no disrespect)

I can start in 2nd, but not 3rd. I can stall in 3rd, when I drive the Insight for a while forget what gear I am in [when in the Mustang] lol

The automatic sucks for choosing gear, especially with the standard tune. I remember test driving a 13 on a lot before I decided I should grab a 12 while it was still new- I don't remember the exact RPM it would get down to, but it definitely wasn't under 800, or even 1000- I want to say 1350 ish was the lowest cruising RPM, but that was about two years ago, now.

[gk_ghig14]

Haha! I really wanted a standard but all the mt82 issues scared me off, especially with my mod plans in a few years. But manual explains the 6th gear thing. It's more of a mechanical thing vs computer based like my auto shifting is

I believe I start in 3rd(that's what my dash says, and it feels that way). Helps a lot in the rain

I wanna say lowest I've seen is like 1200 in 6th, that was right around 45 when I did the manual mode into 6th

I really wish I had more control over my car like you do. Make life so much easier