Cruising Engine RPMs, Gears & Gas Mileage

Lower RPM= less fuel. So just above the stall point would be using the least amount of gas.
But you bought a Dodge Viper as a daily driver. Lets not discuss gas mileage.

Your better off buying a daily driver for the same money you would spend on a gear swap if fuel usage is a concern.

 

What in your mind equals a "safe RPM"?

You've question and logic make no sense to me, sorry I could be of more help.

 

We cruised for hours in 6th gear at 1500rpm and got 21mpg. 2000GTS

 

Seriously?/
Do yourself a favour and get a beater to drive daily. As much as you love eating candy if you eat it every day you are going to hate it. Gas mileage?!!!! Ok the only way you get good gas mileage if you put it in NEAUTRAL and roll it down the hill with the wind.

 

If you want to protect the engine, the worst thing you can do is cruise it at very low rpms under load when the oil and coolant is cold. With your 4.5 mile commute, the motor will not have enough time to heat up and burn off condensation and contaminants out of the oil. Trying to drive at a low rpm and lug it along to save mpg's for such a short communte isn't going to help, in fact is is harder on the gears in the transmission since you're putting more load on them without the lube being brought up to temp.

Doing a gear change will take about 5 to 6 years of driving to pay off in mileage gains (I'm being way generous).

The rpm isn't going to determine mileage as much as engine vacuum....if you put a vacuum gauge on the car you'll find that under certain conditions, lugging the car will give you worst mileage. If you can keep the car under load with the highest amount of vacuum, then you'll get the best mileage. For city type driving, your first four gears give you more than enough flexibility to do this.

Driving the car "aggressive" vs lugging it for better mileage on a 10 mile trip would equate to less than $1.00 per day in savings.

Enjoy your new ride, you're fortunate to be able to use the Viper as your daily driver.

Cheers,
George

 

I think I know what your asking and I don't like to cruise at much less than 15-1800 rpm. Morgen at tombal dodge Said luging these things is really hard on the engine. I bet you would like a 355 or 373 rear end much better. Steve

 

Oh and I would consider getting another car to help subsidize the snake. I'm sure you could get something cheap to drive on crappy days! Steve

 

Dodge Viper=bad gas mileage

Bruce

 

I drove mine daily as transportation when I got it. Did that for about a year. Then finally realized that a Corvette is a much better street car. My Viper is now just a toy for track days. As much fun as these things are, you need an alternate ride for slumming around day to day. It also helps the Viper experience to be more intense.

 

Tow it with corvette and you'll get great milage

 

IDM, as others have suggested, you shouldn't be focused on gas mileage and economical driving styles if you're driving a Viper. I also use my Viper as a daily driver (2010 ACR), and have put 5000+ miles on it in 6 months. I *always* drive it the way it is supposed to be driven, and fill it up with 93 octane when it gets below 1/4 tank. I've never bothered to measure the fuel economy. I've got an Escort 9500ix + Escort Live + Laser Interceptor 4 head unit, so I haven't noticed any issues with gearing and speed limits.

 

Why not let it warm up prior to leaving for work? I would suggest starting it about 5 minutes prior to heading out.

 

Toss the mileage optimization goal out the window. Forget the gears. Drive it. Since your commute is too short (4.5 miles) and your Viper isn't warmed up before going to work then I suggest you leave for work 15 minutes earlier and take the Viper for a warm up cruise, romp around a pre-planned route on your way to or around work. You'll get better gas mileage this way and warm up the Viper. More importantly, it'll put a s***-eating grin on your face when you arrive to work every morning.

 

Highly recommend a second car.

 

The old wives tales and non-sense on this thread are staggering.

Why would need to be above 1500rpm at all times? This means that you will be in 5th gear all the way to 80mph with rpm at 2200+ rpm before a change to 6th gear (rpm is your requested 1500). You can cruise at 60mph in 6th gear with rpm at 1100. You are just loafing and cruising along. There is not need to be in a lower gear unless you are passing, there is hill, hitting late apex at a track, or you are in Mexico racing. Once up to operating temperature, nothing will happen to the engine at that rpm. Granted, you will need more "load" since being 6th gear multiplies down (by 0.5) your engine torque output. However, this does necessarily mean that you will burn more fuel.

Let's now get serious and factual about engine load and how much you are terrorizing the engine at lower rpm. At 1000rpm, our engines only make about 80 horsepower (420 ft-lb * 1000rpm / 5250 = 80 hp). At that rpm, the engine is properly oiled, cooled, executing proper combustion mix, and well under its maximum operating capacity in virtually all aspects. I challenge anyone with any real technical information to come and proof to me how this dangerous to our engines.

Please do come forward and I shall aptly retort.

 

I can appreciate your point . my approach for myself is a New Mustang Convertible for a Daily Driver , and Viper and 2 motorcycles for the FUN Activities .

 

I cruise for hours as well in the 08 SRT-10 6th ~1400 rpm 78 mph ~23 mpg

 

Your big V-10 can lug around pretty well, but it has little satisfaction driving it like that.

Instead of watching your tach, instead feel how well it responds to throttle.

If you add throttle, but the car does not seem to want to accelerate, then you are in a lugging situation. Changing down a gear will not effect your fuel economy, but make your engine much happier.

If you notice bucking, also shift down a gear.

Vipers are actually pretty fuel efficient when driven conservatively, and this is part of their engineering design, but they are not at their best at the lowest possible RPM's.

Since you are driving in a warm climate, your engine will warm up pretty quickly, however no matter how conseratively you drive, you will not attain optimum fuel economy in such a short commute to work. WHen you start out, your engine will be running in a choked, or fuel enrichened state.

If you are going to short shift around town to maximize fuel economy, you will do yourself and your Viper a big favor by taking it out on the freeway for an "Italian Tuneup" every once in a while.

Hope you enjoy your new Viper. They are pretty remarkable cars.

 

Not sure what you mean by the car doesn't feel fast or isn't fast?! I just came out of an 09 Z06 and the Viper would kick it all day and every day.

 

Don't let it drop below 1000 rpm but you can cruise with gentle throttling just above that.

 

The advice about ditching the run-flats is more over safety rather than traction. If they're the original run-flats, they are probably old and hard. They most likely will bite you not necessarily during spirited driving but during an emergency maneuver. Be safe out there!