Gear ratio to hit 20 mpg or close HWY 01 Yukon XL

[TollKeeper]

Its kinda off.. But.. gives an idea.
My 2006 Saab 9-7x 5.3 AWD has the 3.73 Short Wheel Base, weighs 4500 lbs (estimated), and gets 15.8 routinely (AFM/DOD Deleted). Nothing in it but me and my lunch.
My 2004 GMC Envoy 4WD 5.3 has the 3.42 Long Wheel Base, Weighs 5980 lbs (verifed by scale before kids), and gets 16.7 routinely (No AFM/DOD). Plus: 2 kids, 1 Car Seat, 1 Toddler seat, 1 Stroller, 1 wife with her kitchen sink purse, various toys, and kid stuff.

Both are the same truck, except Envoy is a XL. Both are 4L60E.
3.42 only really shine for fuel mileage in highway cruising. If your in the city, its worse than the lower gears.
I will admit I probably loose a few tenths because of the AWD on the Saab.

Based on the OP first post, regearing his truck is not going to help, in fact, it may make it worse.

 

[S33k3r]

AWD is typically going to ding you 1 - 2 mpg, because it cannot be turned off; 4WD is on demand, so you are cruising in 2WD most of the time. How do I know? Our Sierra Denali is AWD, the 2005 Suburban is 4WD on demand. You can also Google discussions on it, iirc.

 

[TollKeeper]

AWD is typically going to ding you 1 - 2 mpg, because it cannot be turned off; 4WD is on demand, so you are cruising in 2WD most of the time. How do I know? Our Sierra Denali is AWD, the 2005 Suburban is 4WD on demand. You can also Google discussions on it, iirc.

No argument there, my point was more for the gearing, and the vast weight difference.

 

[S33k3r]

No argument there, my point was more for the gearing, and the vast weight difference.

Ug. I missed that in your original update. Sorry for that.

One other thing did occur to me, though. If you're dumping seats for MPG, might also want to dump 4WD/QWD. The system fully removed is likely to get another 1 - 2 mpg.

 

[TollKeeper]

For me, to add insult to injury.. The 2006 Caddy Esky I sold last year, 6.0, 4.10 gears, AWD, and 5700 lbs (scaled) got the same as my Saab, 15.8. Bigger truck, fatter truck, lower gears, bigger engine, and the same MPG. WTF!

 

[S33k3r]

For me, to add insult to injury.. The 2006 Caddy Esky I sold last year, 6.0, 4.10 gears, AWD, and 5700 lbs (scaled) got the same as my Saab, 15.8. Bigger truck, fatter truck, lower gears, bigger engine, and the same MPG. WTF!

The short answer: Saab sucks. (I don't think Saab sucks). I think the real issue is that the Saab was owned by GM back then, so it has a lot of the same GM parts as in our trucks. I am just guessing, though.

 

[swathdiver]

We are looking at getting an electric for my wife, between now and 2 years out. It will likely be our last new car purchase ever.

If you keep ticking ten years from now, that electric car is going to need a new battery about then. EVs are more expensive and less enduring still. None of them can do what your 2500s can do.

The Ferd hybrid F150 is pretty cool but not the lightning IMO. They're just not ready to do truck things.

 

[Sparksalot]

If you keep ticking ten years from now, that electric car is going to need a new battery about then. EVs are more expensive and less enduring still. None of them can do what your 2500s can do.

The Ferd hybrid F150 is pretty cool but not the lightning IMO. They're just not ready to do truck things.

Mall Rated!

 

[S33k3r]

If you keep ticking ten years from now, that electric car is going to need a new battery about then. EVs are more expensive and less enduring still. None of them can do what your 2500s can do.

The Ferd hybrid F150 is pretty cool but not the lightning IMO. They're just not ready to do truck things.

If I were getting rid of my trucks, I might be concerned.

 

[LordWayback]

The number one thing you can do is drive with a light foot. Number one thing. Now, in terms of technological solutions, these are the only things I can currently think of:

1) Drive with a light foot. It needs to be emphasized.
2) Convert to efans. They will bump mpg a tiny amount, but they will bump it up.
3) Tune for higher octane.
4) If you are wanting to regear for MPG, I suggest changing your cam so you can develop your torque as low as possible in the RPM band.
5) I have heard a turbo can help but, once again, you have to keep a light foot...
6) Reduce vehicle weight. Take out some seats, for example.
7) improve aerodynamics.
8) Not sure how you would do it, but you could also add active fuel management, theoretically. I mean, I don't advise it, but it would save gas.
9) By a cheap, fuel efficient beater for daily driving, and keep your Yukon for fun. And the beater is likely cheaper than most of the above.

That's all I can think of. Good luck.

I think the junk is one of the biggest factors 99% of the time I don’t need the 3rd row I have tons of junk in the back like pressure washers n stuff , efans?