Re: RE: Gas mileage and gear ratio

From: Alex Harris (jetcity@swbell.net)
Date: Fri Mar 09 2001 - 17:40:39 EST


Hmm. Well, I'd probably drive in whatever gear allowed me to cruise at the
RPM I like. Maybe I'll tool down the boulevard in 4th rather than 3rd...

I've always felt that I get crappy mileage in town because I accelerate
hard; it's the stops and starts. I thought that if I made accelerating
easier work for the engine I should be able to knock a chunk of that off.
I'll also be switching to 31" tires, but my final axle ratio will still be
going up from 2.34 to 2.86 and my effective ratio will be 3.40 (looking at
that makes me think 4.10's... heh heh).

As for the highway speeds someone mentioned, right now at 70 mph I'm turning
just about 2000 RPM. The tech at Randy's Ring and Pinion told me that's a
bit low, and if I'm turning 2300 (which is what it'll be with the new
gears/tires) I'll probably get better gas mileage because the engine
actually won't be working as hard to keep my speed up. Also, since it's so
low at present, I spend a lot of time downshifting to fourth on the highway
when I need a bit of acceleration.

Blah blah blah... I'll be interested in seeing what happens -- and rest
assured the whole DML will find out.

Ciao!

- Alex

> From: Ronald Wong <ron-wong@home.com>
>
> More than likely it'll go down. Your engine will be running higher RPMs
> more of the time. This will more than offset the work required to get up to
> speed.
>
> Ron

> -----Original Message-----
> From: owner-dakota-truck@buffnet.net
> [mailto:owner-dakota-truck@buffnet.net]On Behalf Of Alex Harris
>
> Here's a question... when I switch from 3.21's to 3.92's will my city gas
> mileage go up? Seems to me the engine will have to work less to get the
> truck up to speed. Any experience with this, anyone?
>
> - Alex
>



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