2.7 MPG and RPM shift points

[spb350]

I'm just about to start driving my newly acquired 76 911 with a 2.7 a lot more now that the weather is starting to cool down here in AZ. I'm wondering about mpg and proper shift points for my car. Obviously running the car up to 6000 rpm's on every shift is not great for mpg but where is the optimal shift point for a 2.7. Where are you other 2.7 guys shifting and what kind of mpg are you getting in the city and on the hwy? Thanks

[Jerome74911S]

Your question is very broad.

That said, my 2.7 (1975 CIS engine) gets 30.2 mpg when driven at a steady 65 mph on the highway. It's not often driven that way, though. As for city driving, I never drive in the city, so my experience won't help you much in this regard.

But, shift points are another issue. Are you interested in driving it in a 'sporting' manner, or for lowest fuel consumption, or maximum performance on a track, or what?

The 2.7 engines are known to be easy revving engines; they like to spin. Of course, on a day-to-day basis, you won't go to 6,000+ rpm every time you shift the thing, but, and this is more important, don't let the revs drop too low. It will not be happy lugging along at 2,000 rpm, especially in a higher gear.

You seem to be interested in good fuel economy, but this car has other ideas. It's a sports car, after all, so drive it in a sporting manner and be happy.

In ordinary situations I generally shift gears at 4,000 to 4,500 rpm, unless the oil is cold. Going judiciously above or below this rpm range is fine, but you will find that you do much of your cruising at around 3,000 rpm.

Just don't lug it.

[obscene]

my 2.7 with weber carbs averages 13mpg. it almost never sees long stretches of highway cruising and I normally shift around 4000-4500 rpm.

[spb350]

MPG is not really my biggest concern its more about the optimal shift point for the engine. My motor only has about 600 miles on it and I don't really want to over rev and I don't want to lug it. I know it hates anything under 2000 rpm's, driving slow in my neighborhood is a pain, 1st seems to be reving and 2nd is lugging. I think my last tank of mixed driving and shifting in the 4-5000 rpm range netted 16 mpg. Is that about average?

[Uncle Enzo]

Originally Posted by obscene

my 2.7 with weber carbs averages 13mpg. it almost never sees long stretches of highway cruising and I normally shift around 4000-4500 rpm.

lol...yup. I am getting about 18mpg and I drive like a puss in my carbed 2.7

[Sboxin]

spb350

You might want to stop by the AZPCA DE event this Saturday and talk with a few Porsche owners about your new car questions. You don't need to be participant to
visit the event at AMP in Litchfield Park -- just sign the waver at the entrance.

Upcoming Events | Driver Education | AZ PCA

Regards,

[911SauCy]

TO answer your inquiry directly

It's SPG, not MPG, that matters. You should be shifting above 4k...the SPG will be inversely related to your MPG which is the perfect symbiotic relationship for a new Porsche owner and his/her car.

[spb350]

Originally Posted by Sboxin

spb350

You might want to stop by the AZPCA DE event this Saturday and talk with a few Porsche owners about your new car questions. You don't need to be participant to
visit the event at AMP in Litchfield Park -- just sign the waver at the entrance.

Upcoming Events | Driver Education | AZ PCA

Regards,

Thanks for the heads up, I have lived here about three years and never knew that track was there. I'm not sure my car would pass the inspection at this point but I think I might go to check it out, it looks like fun.

SPG = Smiles Per Gallon I assume, I do enjoy the higher rpm's and even at 16 mpg it is way better then my other toy.

[JohnJL]

I get about 2.7 mpg in the supercharged car at the track.

[SkunkWorks]

Originally Posted by 911SauCy

TO answer your inquiry directly

It's SPG, not MPG, that matters. You should be shifting above 4k...the SPG will be inversely related to your MPG which is the perfect symbiotic relationship for a new Porsche owner and his/her car.