Pennock's Fiero Forum
  Technical Discussion & Questions
  Why do certain v6 Fieros have gauges that only go up to 80mph

Post New Topic  Post A Reply
Email This Page to Someone! | Printable Version


next newest topic | next oldest topic
Why do certain v6 Fieros have gauges that only go up to 80mph by Decaffrican
Started on: 10-20-2021 05:07 AM
Replies: 11 (533 views)
Last post by: MarkS on 10-22-2021 07:39 PM
Decaffrican
Member
Posts: 18
From: California
Registered: Oct 2021


Feedback score: N/A
Leave feedback

Rate this member

Report this Post10-20-2021 05:07 AM Click Here to See the Profile for DecaffricanSend a Private Message to DecaffricanEdit/Delete MessageReply w/QuoteDirect Link to This Post
I bought my 85 v6 Fiero knowing it wasn't a GT but figured the difference between trims came from the difference in engine/suspension/bodypanels...? I'm pretty new to the car scene, and even though I now own one, I'm still a hardcore newbie when it comes to knowledge about Fieros.
IP: Logged
PFF
System Bot
oneinch
Member
Posts: 119
From: PA
Registered: Oct 2020


Feedback score: N/A
Leave feedback

Rate this member

Report this Post10-20-2021 07:20 AM Click Here to See the Profile for oneinchSend a Private Message to oneinchEdit/Delete MessageReply w/QuoteDirect Link to This Post
This is not an answer to your question. Just a comment. .... My '88 Formula has a 120 speedo. I would prefer the 80 speed myself because of the greater detail in the dial. I don't drive 80 so I don't need speed markings that high. I know I know. The 120 speedo looks cooler. Here's a shot at an answer: the 4's get 80, the 6's get 120.

------------------
Stanton
'88 Formula, red on gray

IP: Logged
fierofool
Member
Posts: 13003
From: Auburn, Georgia USA
Registered: Jan 2002


Feedback score:    (13)
Leave feedback





Total ratings: 153
Rate this member

Report this Post10-20-2021 07:24 AM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageSend a Private Message to fierofoolEdit/Delete MessageReply w/QuoteDirect Link to This Post
The 85 V6 was available in the GT trim and the SE trim. Both had the 85mph speedometers. All 4 cylinder Fieros had the 85mph speedometers. The 120mph speedometers didn't appear until 86 and was available in the GT trim, as well as the SE trim.

The 86 and 87SE trim is identical to the 85GT body. The 86 and 87 SE's were also available with a choice of 4 or 6 cylinders even though they had the aero trim package like the 85GT and they had the 120 speedometeer. The 'bumperpad' 86 which is the same as your 85SE trim however, only came as a 4 cylinder. I believe it had the 85mph speedometer.
IP: Logged
olejoedad
Member
Posts: 19994
From: Back home again in Indiana
Registered: May 2004


Feedback score: (5)
Leave feedback





Total ratings: 201
Rate this member

Report this Post10-20-2021 08:02 AM Click Here to See the Profile for olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
The good news is that the 85 mph and 120 mph speedos are plug and play as far as interchangeablity.

My 86 SE (V-6/4 speed) came with an 85 mph speedo, but it was quickly replaced.
IP: Logged
RWDPLZ
Member
Posts: 15087
From:
Registered: May 2002


Feedback score:    (11)
Leave feedback





Total ratings: 305
Rate this member

Report this Post10-20-2021 08:24 AM Click Here to See the Profile for RWDPLZSend a Private Message to RWDPLZEdit/Delete MessageReply w/QuoteDirect Link to This Post
Many cars had speedometers that only went to 85 MPH, due to a NHTSA mandate during the 70's oil crisis

http://www.classic-car-hist...om/85-mph-speedo.htm
IP: Logged
Wichita
Member
Posts: 20709
From: Wichita, Kansas
Registered: Jun 2002


Feedback score: N/A
Leave feedback





Total ratings: 322
Rate this member

Report this Post10-20-2021 08:48 AM Click Here to See the Profile for WichitaSend a Private Message to WichitaEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by RWDPLZ:

Many cars had speedometers that only went to 85 MPH, due to a NHTSA mandate during the 70's oil crisis

http://www.classic-car-hist...om/85-mph-speedo.htm


Basically RWDPLZ nailed it.

Back in the 70's, the top speed limit on the Interstates and Highways was 55mph as the National Speed Limit. They did up it to 65mph in the 80's.

It wasn't until 1996, when the Federal Government gave the speed limit decisions back to the respective states. Now you will see 70 to 75mph as very common, with even some 80-85mph speed limits.

From my understanding, that cars in the 70's - 80's and even to the 90's the engines were engineered and tuned to maximum efficiency at 55mph because of the National Speed Limit law enacted in the 70's.




IP: Logged
ZaraSpOOk
Member
Posts: 256
From: Rosemount, MN
Registered: Sep 2010


Feedback score: N/A
Leave feedback

Rate this member

Report this Post10-21-2021 02:25 PM Click Here to See the Profile for ZaraSpOOkSend a Private Message to ZaraSpOOkEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by oneinch:

This is not an answer to your question. Just a comment. .... My '88 Formula has a 120 speedo. I would prefer the 80 speed myself because of the greater detail in the dial. I don't drive 80 so I don't need speed markings that high. I know I know. The 120 speedo looks cooler.



I can only recall being 90 or over twice in the 30+ years I have owned mine.
But then I drive two lane blacktop over 90% of the time
Reading the 120 speedo is indeed difficult, and the red line at 55 is of no help today, speed limits here are usually 60 on two lane, 70 on 4, 55 is rarely the speed limit.

FWIW, the speedo on my Vette goes to 200
I've done 165, 140 or more numerous times

IP: Logged
Dennis LaGrua
Member
Posts: 16138
From: Hillsborough, NJ U.S.A.
Registered: May 2000


Feedback score:    (13)
Leave feedback





Total ratings: 326
Rate this member

Report this Post10-21-2021 02:37 PM Click Here to See the Profile for Dennis LaGruaSend a Private Message to Dennis LaGruaEdit/Delete MessageReply w/QuoteDirect Link to This Post
That 80 mph speedometer is a real inconvenience. I only have it on my 85GT ragtop but on the turnpike in my 87GT in some segments speeds of over 90 are common. I travel almost always over 80 mph. The good news like Joe has said the 120 mph gauge console drops right in.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

[This message has been edited by Dennis LaGrua (edited 10-21-2021).]

IP: Logged
MarkS
Member
Posts: 727
From: Flemington, NJ
Registered: Mar 2006


Feedback score: N/A
Leave feedback

Rate this member

Report this Post10-21-2021 03:40 PM Click Here to See the Profile for MarkSSend a Private Message to MarkSEdit/Delete MessageReply w/QuoteDirect Link to This Post
Joan Claybrook '79. It took a few years to undo that one.
IP: Logged
Dennis LaGrua
Member
Posts: 16138
From: Hillsborough, NJ U.S.A.
Registered: May 2000


Feedback score:    (13)
Leave feedback





Total ratings: 326
Rate this member

Report this Post10-21-2021 05:26 PM Click Here to See the Profile for Dennis LaGruaSend a Private Message to Dennis LaGruaEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by MarkS:

Joan Claybrook '79. It took a few years to undo that one.


Yes as head of the NHTSA she was the one responsible to the 80 mph speedometers, the collapsible front bumpers, mandatory air bags, removal of hood ornaments, and imposing tough crash standards. Like most Socialists she insisted that government knew what was best for everyone and car prices skyrocketed because of these mandatory changes.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

IP: Logged
pmbrunelle
Member
Posts: 4651
From: Grand-Mère, Québec
Registered: Sep 2008


Feedback score: N/A
Leave feedback





Total ratings: 63
Rate this member

Report this Post10-22-2021 06:37 PM Click Here to See the Profile for pmbrunelleSend a Private Message to pmbrunelleEdit/Delete MessageReply w/QuoteDirect Link to This Post
I like the 140 km/h speedo, since it gives wider gaps between the graduations.

Speed limit on highways here is 100 km/h, and the maximum tolerated by police is 120 km/h. A typical cruise speed is 110 km/h.

Above 140 km/h, I don't really need to know my speed accurately... it's big ticket time.

I know that my car hits 204 km/h at 6000 RPM, so I can use the tachometer to estimate road speed when the speedo is out-of-range.
IP: Logged
PFF
System Bot
MarkS
Member
Posts: 727
From: Flemington, NJ
Registered: Mar 2006


Feedback score: N/A
Leave feedback

Rate this member

Report this Post10-22-2021 07:39 PM Click Here to See the Profile for MarkSSend a Private Message to MarkSEdit/Delete MessageReply w/QuoteDirect Link to This Post
I remember the 85 mph speedo in my 85 GT I bought new. As I was fairly young and pretty much fearless, taking my new car out on the hwy and nailing the right pedal for all it was worth was ehhh typical. Well into 3 digits speed, the 85 speedo would go nuts. The speedo needle swinging wildly like "where the hell am I, please help!?" This is something you can use when asking someone "how fast did you get this thing going" on an 85mph speedo V6? If they say "oh I buried the speedo" well, they weren't going that fast.

[This message has been edited by MarkS (edited 10-22-2021).]

IP: Logged

next newest topic | next oldest topic

All times are ET (US)

Post New Topic  Post A Reply
Hop to:

Contact Us | Back To Main Page

Advertizing on PFF | Fiero Parts Vendors
PFF Merchandise | Fiero Gallery
Real-Time Chat | Fiero Related Auctions on eBay



Copyright (c) 1999, C. Pennock