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Posted by: pbanders May 3 2007, 10:27 AM

There are a lot of apocryphal MPG figures out there for the 1.7L 914's. I was wondering what the factory said the MPG was. I poked around on the web and finally found a reference at Automobile Atlanta that George took from some ancient factory brochure. Here's the image:



Pretty blurry! But you can see under the "Performance" section, the third entry is "Fuel Consumption", and it has a figure for the 1.7L. It's pretty hard to read, but if you blow it up, I've figured out that it's:

approx. 26.2 mpg (9.0 l/100 km)

If you use Google calculator, you can verify that 26.2 mpg is equal to 9.0 l/100 km, so it makes sense.

There are no particulars on the driving conditions for this figure, it's probably reasonable to assume this is a combination of city and highway driving.

Anyone else have other factory or EPA figures on the 1.7, 1.8, and 2.0L cars?

Posted by: Bleyseng May 3 2007, 11:05 AM

just this ad


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Posted by: Bleyseng May 3 2007, 11:07 AM

2.0L MPG


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Posted by: andys May 3 2007, 11:27 AM

It's been, well, 30+ years, but it seems my '73 2.0L got something like 29-31MPG all the time. More on long highway trips. Back then, MPG wasn't the concern that it is today, so little emphasis was placed on mileage. If you calculate it by today's California "specially formulated gas", you'll lose 2 or 3 MPG.

Andys

Posted by: smontanaro May 3 2007, 11:41 AM

yeah, with my '73 1.7L I used to get 34-35 mpg on long highway drives so 30-ish overall sounds about right.

Skip

Posted by: pbanders May 3 2007, 11:41 AM

Good point about how oxygenated fuels reduce mileage. Looks like the 1.7L today would be just under 30 mpg, the 2.0L, just under 25 mpg. My newly rebuilt 2.0L has been getting about 21 mpg in mixed city driving recently, with no attempt at being economical - maybe I'll try running a bit leaner.

Edited - I read the ad for the 2.0L wrong, I thought it said 25 mpg, it actually says 23 mpg. Maybe 21 mpg with today's fuel isn't that bad.

Posted by: andys May 3 2007, 12:33 PM

I just read the '74 2.0L ad. It claims 350 miles on a tank of gas. Seems odd, as I remember being able to comfortable put down 400+ miles and still have gas left in the tank. Perhaps they purposely under rated them?

Andys

Posted by: pbanders May 3 2007, 12:57 PM

Yeah - and I didn't recognize that the "29 MPG Porsche" ad isn't talking about the 1.7, it's talking about the 2.0, in the context of highway driving. 29 mpg for 16.4 gal is a range of 475 miles, so 400+ per tankful on the highway makes sense.

Posted by: pbanders May 3 2007, 01:03 PM

It would be interesting to tune a 1.7L (e.g. adjust the MPS) for as lean as could be tolerated, and do a 100 mile highway MPG test, then calculate the range. From some of the stories we've heard here, 40 mpg for a 1.7L isn't unheard of. At 40 mpg, that's a range of 656 miles - I'm pretty sure that's more than even the MB diesels!

Posted by: ChrisNPDrider May 3 2007, 01:26 PM

My 1.7 is running pretty lean and I get about 35 mpg hwy, less driving in the city and AXing
My concern is that after an hour at 70 mph/3.5-4K rpms (195/50 tires) my oil temps are 200-210 F on the dip stick gauge, which is a decent thermometer.
I'm afraid going too lean, driving up a long hill, head and oil temps would be needing a close watch. Please comment, as I wish to get the most MPG! I will have 1 5/8" Eurorace header on 1.7 stock D-jet, and will probably use a modified high flow air intake (K&N style) soon to support the header

Posted by: Root_Werks May 3 2007, 01:28 PM

I have had a couple of stock injected 1.7 914's that have gotten over 30mpg average easy. If you keep them in good tune and everything is healthy, they should do well.

I am trying to buy back a 73' 1.7 car right now just to have something to sputter around in that is fun and gets good MPG.

Posted by: Demick May 3 2007, 01:30 PM

Ummm. Ever heard of the 1973 Arab Oil Embargo? Price of crude oil quadrupled in 1974. Certainly the reason for "the 29mpg porsche" ad. MPG got plenty of attention in the mid '70's, and a whole lot more in the late '70's than it gets now.

Posted by: DSM May 3 2007, 01:38 PM

I regularly saw 35-36mpg out of a 1.7 with dual ICTs(?) back in the early eighties.
I keep thinking about building a 914 TDI. With a taller R&P I'm betting 50+mpg would be easy. My VW caddy gets 45. 52hp is no fun though...

Posted by: pbanders May 3 2007, 06:47 PM

Doesn't Subi have a flat-four diesel 2.0L?

Posted by: BarberDave May 4 2007, 06:10 AM

I just returned from a 1,000 mile trip to Hershey and back. I got 27 mpg on my 1.7 . However 2 yrs. ago with another 1.7 and Weber 34 ITC's i regularly got 39 mph. Current engine has 40 Webers. Dave