4.5 Vs. 4.9

[pithi69]

Simple question: Which engine is better? The v8 4.5 or the v8 4.9 and why? Probably more horsepower and efficiency or something obvious like that, but i'm just curious because i'm getting a 1990 Deville 4.5 and couple years later they put a 4.9 in it and i'm kind of mad but if it's nothing big i'll be fine...

[ilgoldstein]

I've had both. My 89 has the 4.5 and my 93 had the 4.9. I got rid of the '93 because there were too many things going wrong with it to make it worth fixing, it was my Dad's car when he died. Got it with about 100K on it, I drove it about 40K and aside from some fuel injector issues, it was a good strong engine.

The 4.5 has never given me any trouble. I got it when it had about 32K and it has 104K on it now, never a problem with the engine. (egr once.)

My smog guy says he used to work the line at Cadillac, and the 4.5 is a great engine.

The 4.9 uses permium (I used midgrade) and yes, it had more power.

I think either would be a great choice, but you will save a lot on gas with the 4.5.

Enjoy! Its a Cadillac!

[D Spec D1]

The 4.9 delivers 200hp and 275ft/lbs of torque, whereas the 4.5 delivered a maximum of 180hp (1990 PFI models only) and I believe 245ft/lbs, though that may not be correct. 4.9's have less problems (The 4.9 is the lowest warranty claim engine Cadillac has ever built), but aside from a few changes, they are the same engine. The 4.9 is a stroked 4.5, and going further back, the 4.5 is just a bored 4.1.

They switched to the 4.9 in 1991, and aside from the 20hp, you also lose out on a much better looking vehicle IMHO.

[pithi69]

Wow, thanks, that's pretty much all I needed to know...Awesome, any exhaust preferences?

[D Spec D1]

I've got the stock mandrel bent 2.75" exhaust on my car going back to an OTTO Racing muffler, it is fiberglass filled with dual resonated outlets on it.

My car's exhaust clip

That was the day after I got it put on, before it was fully worn in.

My CAI clip

The 4.5 in general sounds the same as a 4.9, so these clips should give you a general idea of how a modded 4.5 should sound - In a word, evil.

[jp76]

I just bought a 93 deville sedan with the gold trim , love it. Anyways, does anyone know the 0-60 and qmile time on it. I know I have seen on consumer report that the 4.5 from 90 did around 9.5 but it didn't mention anything in the 11th gen years besides that. Any info. would be great.

[maxwedge]

Originally Posted by jp76

I just bought a 93 deville sedan with the gold trim , love it. Anyways, does anyone know the 0-60 and qmile time on it. I know I have seen on consumer report that the 4.5 from 90 did around 9.5 but it didn't mention anything in the 11th gen years besides that. Any info. would be great.

You really should start a new thread, this is 6 months old.

[jp76]

I understand your position, but I just spent close to 30 min. looking through 26 pages trying to find specific answers to a few q's. I found all but 1 and would like to know as I own a sports car and I am interested in that sort of thing. The reason I ask though is because this is a caddy that is not meant to be raced at the track or beat around. I would like to keep it in mint condition as it only has 71k pampered miles on it.

[ilgoldstein]

Yea, but now you are talking about exhausts, times, etc. Too much jumble.

[jp76]

I never said anything about exhausts, etc.. I would never mod my cad or camry, that's what my mitsibishi is for.

[devilleish]

Anyone know if 4.9 cylinder liners will fit in a 4.1 RWD with the proper reciprocating assembly? Wanting more and about to tear into another engine. Also, will the 4.9 cam work?