Cruising around town at 30 mph what gear//rpm do you guys have it at hbout 20? For best gas milage I know its not a honda blah blah but some people don't like to fill up on gas twice a week so stfu....is there a rule of thumb to keep it above 1.5k rpms or something of that nature? I'd like to know what you guys do, thanks!

 

4th. With the 4.10's I can be in 5th at 35, but below that the motor struggles too much for my tastes.

 

I spent some time experimenting with cruising in different gears while watching the MAF. At any given constant cruising speed, you basically consume the least air and therefore the least fuel by keeping it at the lowest RPM possible. For all practical purposes, there is no "keep it above" threshold - the lower the revs, the more economical it is. Of course, you don't want to lug it down so low that it starts knocking, bucking, or otherwise running rough, so 1200 is about the practical limit, and you have to be fairly gentle on the throttle that low. Throttle response will be a lot better around 1400+, and I usually try to cruise at around 1400~1700, but don't kid yourself - throttle response and economy don't go together.

 

Start in 3rd and shift into 5th at 25 I'll to 6th occasionally under 35 but why? Even the 402 with 3.73:1 rear doesn't have the low rpm grunt needed for that gear. I usually get about 18-20 around town taking it moderatly easy on the throttle and the shift points.

 

I don't go quite THAT far, but shifting at ~1500 is quite driveable. With my 2.97 trans, which is similiar to running 3.73s, I basically shift into 2nd as soon as the car is out of the driveway, and I didn't go much further in first with the stock trans.

 

stay over 1500rpm but under 2500 when crusing, and baby the throttle

 

Also, shift 1-3-5. That will save gas, too. I haven't babied my car lately because I have driven it twice since October but I put 10k miles on it between March and October and when I was trying to save gas, I went light-throttle and shifted from 1st to 3rd around 2kish and 3rd to 5th around 2kish. I try to stay under 1700rpms for cruising.

 

That rpm range may be more fun, but it certainly won't help the mileage.