HOW MANY MPG

PUMANIAC · Post by **PUMANIAC** » Thu Jun 20, 2002 5:24 pm

What kind of fuel consumption should I expect from a stock dp 1600 with a single stock carb? I am not sure of the compression. Will higher compression give me better mpg?

Class 11 streeter · Post by **Class 11 streeter** » Thu Jun 20, 2002 6:45 pm

What kind of mileage should your 1600 DP stock carb give you, you ask?

Well, how do you drive? Leadfoot?

What is the engine in? A bug or a bus?

How mechanically sound is the engine?

If its a bug, is it a Baja running 30" tires?

All this and more affects the mileage. Also, no two identically build engines will quite run the same or get the exact same mileage in the same car.

bmorganchico · Post by **bmorganchico** » Thu Jun 20, 2002 7:07 pm

This is the Type 1 forum, so we can definitly assume it is a Bug. But since we cant determine much else, what do you get in your stock bugs? I would be interested to know.

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Who needs power?

Well, me of course!
69 VW Project....damn 1600, i need a 2275

Bare · Post by **Bare** » Thu Jun 20, 2002 7:16 pm

My '71 SB (which I bought new) generally gets very low 20's MPG. depending on how long ago it had a good tuneup.. these things get crappy mileage by current standards.. and DON"T forget they now need at least a mid octane fuel onna stock engine.. fuel quality has unfortunately deteriorated over the years .. therefor raising the CR is not a clever plan Mate, cuz you will need to run hi-test just to avoid 'pinging'.

PUMANIAC · Post by **PUMANIAC** » Thu Jun 20, 2002 7:31 pm

My car is a PUMA that has a stock 1600 in it. It revs about 4000 rpm at 70mph. The car is light (1600 lbs.) but I tend to drive it on the hard side! I have 911 Fuchs (16X6&7) wheels on it which does not help I guess. Does anyone have experience with a freeway flyer (3.88 r&p) tranny in a stock application?

Thanks BOYS

aussiebug · Post by **aussiebug** » Thu Jun 20, 2002 10:55 pm

1970 bug with 1600sp, 30PICT/2 carby and vacuum distributor - 29.8mpg (US gals) measured over 248,000 miles I've driven the car (That's 36mpg - Imp gals, which sounds even better!).

1600dp in a 68 bug (same weight as the 70) with the SAME 30PICT/2 carby and vacuum distributor - 27.8mpg (US gals) measured over about 1000 miles.

Same 1600dp with the air-leaky 34PICT/3 it came with when I bought it - terrible - about 23mpg!

Expect increased fuel consumption when using a 009 distributor, a lead foot, larger carbs, larger capacity, dragging brakes or any combo of the above

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Post by **Marc** » Fri Jun 21, 2002 6:57 am

Stone-stock 1972 engine in a `69 Beetle, (34 PICT-3, stock muffler and aircleaner, but an 009 distributor set at 31.5° total- with NO flatspot), has almost 175,000 on it (it was a core that I resurrected for temporary propulsion ten years ago and it just keeps on tickin' so I'm driving it into the ground - has low compression on one hole and a cracked head that occasionally ejects a sparkplug on another, but it takes me back and forth to work just fine).
Stock gears/tire size, overall I get exactly 25mpg tank after tank after tank (mostly back roads and stop-and-go traffic, with about 15 miles of 60mph in the morning). On a long highway trip (I don't trust it for those anymore!) it used to pull down just over 30 at 65-70mph.
Point is, if you get less than this tired old turd does something isn't right or you have a heavy foot.
P.S. The early dualports with flattop pistons had a compression ratio of ~7.64:1 and need midrange gas like Bare says, but a `72 is 7.3:1, and I can run the cheapest gas I can find (ARCO 87 with 10% ethanol). Nobody bothers to use dishtop pistons on a rebuild, so unless they're smart enough to increase the deck to hold the C.R. down, regular gas isn't good enough.
Higher C.R. will increase both power and mileage but not enough to justify the increased fuel cost in my opinion.

[This message has been edited by Marc (edited 06-21-2002).]

Post by **Marc** » Fri Jun 21, 2002 7:33 am

<BLOCKQUOTE>quote:<HR>Originally posted by PUMANIAC:
My car is a PUMA that has a stock 1600 in it. It revs about 4000 rpm at 70mph. The car is light (1600 lbs.) but I tend to drive it on the hard side! I have 911 Fuchs (16X6&7) wheels on it which does not help I guess. Does anyone have experience with a freeway flyer (3.88 r&p) tranny in a stock application?

Thanks BOYS<HR></BLOCKQUOTE>

So HOW tall are these tires? Because a 25" tall tire has an effective circumference of ~77", which would make for 3525 RPM at 70MPH assuming a 4.125:1 ring & pinion and a stock .89:1 4th. 4000 RPM would give you ~79MPH. If the Puma comes with a 4.375 R&P then the RPM per MPH would be 6% higher - do you know what the ratio is in it? What letter(s) does the trans serial number start with?

The 3.875:1 ring & pinion transmissions all came with a .93:1 4th, so although 1st, 2nd, and 3rd are 6% taller than with a 4.125 ring & pinion, 4th is only ~1.5% taller. Hardly a "freeway flyer", more of a "slug on sidestreets" combo, but if your car is really that light it should be fine. You need to have a custom-built trans with an earlier .89 (or an even taller ratio from a bus) 4th grafted in to make any significant change on the highway. Too tall of a gear can cause overheating and loss of fuel economy, too (which is why the factory changed 4th when they went to 3.875) so don't overdo it.

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rich2481 · Post by **rich2481** » Fri Jun 21, 2002 8:07 am

I always get 25-27 MPG in my 72 SB.

Sabrinafair · Post by **Sabrinafair** » Fri Jun 21, 2002 8:38 am

What about the older models like '65 or '66?

By the way, my friend's '78 Rabbit got about 40mpg on a trip down the California coast line! $800 car and it drove like a dream!

Post by **Marc** » Fri Jun 21, 2002 9:06 am

<BLOCKQUOTE>quote:<HR>Originally posted by Sabrinafair:
What about the older models like '65 or '66?

By the way, my friend's '78 Rabbit got about 40mpg on a trip down the California coast line! $800 car and it drove like a dream!<HR></BLOCKQUOTE>

The pre-`67 cars had the "short" 4.375:1 ring & pinion ratio (6% lower-geared than the ones we've been talking about) which makes them spunky in town but costs maybe one mile per gallon at 60. The early cars' lighter bodies give them the mileage advantage over later Beetles in around-town driving. It's possible to build an engine for a Beetle that can get 40MPG highway and still have enough power to get out of the way, but don't expect that much from a standard engine. Low to mid `30s on the highway is about the highest expectation you should have.

There's nothing in common between a Beetle and a Rabbit but the VW emblem (the Rabbit is more of a German Fiat than a "real" VW).
The `78/`79 Rabbits came with smaller engines than the `76/77 cars in reaction to the late-70s fuel crisis and they do sip fuel.
Newer cars with more sophisticated engine management systems will get better mileage than Beetles as a rule.

[This message has been edited by Marc (edited 06-21-2002).]

Sabrinafair · Post by **Sabrinafair** » Fri Jun 21, 2002 10:13 am

Nope, hers was white...

Post by **Marc** » Fri Jun 21, 2002 12:10 pm

<BLOCKQUOTE>quote:<HR>Originally posted by Bare:
...seems everyone gets better mileage than my Beetle ...B]<HR></BLOCKQUOTE>

Low 20s isn't disgaceful overall, especially if you spend a lot of time in traffic/lower gears, but your highway mileage should be better.
Was your bunny the 1457 with 1-bbl carb or the 1588 FI? I've heard that the small motor with carb actually got worse mileage - it was only thought up in order to offer a lower price to get you to the dealer in the Yugo days, they never really intended to produce any until someone sued them over it.
I do know it's a pain to find carb parts for.

[This message has been edited by Marc (edited 06-21-2002).]

Bare · Post by **Bare** » Fri Jun 21, 2002 11:49 pm

seems everyone gets better mileage than my Beetle

, not knowing why, might be some truth stretching or might not.. but It's original and has 155k fastidiously maintained miles.. so far.
My '80 Rabbit was consistently burning about a gallon an hour running the I-5 north of S.F. ... not really a taxing road tho.