Optimum rpm range around town and cruising around 70mph? Options

[Geezer914]

What is the optimum rpm range for cruising around town or on the highway at 70 mph?

[emerygt350]

My stock 2.0 definitely likes 3k. At 60 in fifth I am around 2800 but the heads keep cool in mine (although I do have an afr gauge, a rebuilt and home tuned mps so I know it is getting a good mix at that rpm and vacuum level). Head temps on a hot day stay between 280 and 310 (at 60). At 70 I am around 3100. The head temps stay around 310 -360. Climbs will bring it into that upper range and up to 375. Around town 260.
My oil stays nice and cool (210), never more than 230 by my gauge. Switching to the Mobil1 0w40 has really helped with oil temp. You lose a little pressure but I think the extra flow is worth it.

Fuel consumption is an interesting one. If I don't drive like an idiot it gets really good mileage. I have a vacuum gauge on the dash and it seems "cruising" is always in the range on 12 -15 lbs. There is probably some math or something that would allow us to figure out where the perfect spot would be for these engines. Lugging is bad on fuel but so is really high rpms. I suspect at 45, 4th gear is better in mpg than 5th, but I bet at 60 5th is better than 4th (on a flat).

[DRPHIL914]

My stock 2.0 definitely likes 3k. At 60 in fifth I am around 2800 but the heads keep cool in mine (although I do have an afr gauge, a rebuilt and home tuned mps so I know it is getting a good mix at that rpm and vacuum level). Head temps on a hot day stay between 280 and 310 (at 60). At 70 I am around 3100. The head temps stay around 310 -360. Climbs will bring it into that upper range and up to 375. Around town 260.
My oil stays nice and cool (210), never more than 230 by my gauge. Switching to the Mobil1 0w40 has really helped with oil temp. You lose a little pressure but I think the extra flow is worth it.

Fuel consumption is an interesting one. If I don't drive like an idiot it gets really good mileage. I have a vacuum gauge on the dash and it seems "cruising" is always in the range on 12 -15 lbs. There is probably some math or something that would allow us to figure out where the perfect spot would be for these engines. Lugging is bad on fuel but so is really high rpms. I suspect at 45, 4th gear is better in mpg than 5th, but I bet at 60 5th is better than 4th (on a flat).

(IMG:style_emoticons/default/agree.gif)
My numbers for both oil and head temps with my 2056 are very similar to this, but with the caveat that i have an aux oil cooler, that has made a huge difference keeping my oil temps good. i run the DT , brad penn or Valvoline 20/50 but had thought about using a 10-40 of same/similar racing oil with high ZPPD to help that flow as you mention. i have read that helps with overall engine temps and better lube at start up.
Factory recommendations were for 30wt summer and 10wt winter that's what's in the manual and the Haynes, but i digress, i don't want to flood your thread with oil weight discussions - back on track for the O.P.- don't lug it, i cruise around 75mph and rpms will be in the 3500-3800 range i think, and around town or local highway always in 4th and above 3000rpm for better air flow for head cooling

there are other factors for the RPM level, like tire/rim diameter. i am very close to stock, but at one time i had smaller lower profile wheels and my speedo was way off and the rpms were probably 4-500 higher.

Phil